Dette emne vil diskutere flere måder at vende en streng på i programmeringssproget C. Vende en streng er den teknik, der vender eller ændrer rækkefølgen af ​​en given streng, så det sidste tegn i strengen bliver det første tegn i strengen og så videre. Desuden kan vi også kontrollere palindromet for den givne streng ved at vende den oprindelige streng.

For eksempel indtaster vi en streng ' ÆBLE ', og brug derefter den omvendte algoritme. Den omvendte algoritme returnerer strengen ' ELPPA ' som er helt omvendt af den originale streng.

Forskellige måder at finde bagsiden af ​​en streng i C

Følgende er de forskellige måder at finde det omvendte af en streng i programmeringssproget C:

1. Vend en streng ved hjælp af strrev()-funktionen
2. Vend en streng uden at bruge biblioteksfunktionen
3. Vend en streng ved hjælp af rekursionsfunktionen
4. Vend en streng ved at bruge for loop
5. Vend en streng ved hjælp af while-løkke
6. Vend en streng ved hjælp af pegepinde
7. Vend en streng for at tjekke for palindrom

Program 1: Udskriv bagsiden af ​​en streng ved hjælp af funktionen strrev().

Lad os overveje et eksempel for at udskrive det omvendte af en streng ved hjælp af strrev()-funktionen.

Program1.c

objekt lighed i java

 #include #include int main() { char str[40]; // declare the size of character string printf (' 
 Enter a string to be reversed: '); scanf ('%s', str); // use strrev() function to reverse a string printf (' 
 After the reverse of a string: %s ', strrev(str)); return 0; } 

Produktion

 Enter a string to be reversed: AMBULANCE After the reverse of a string: ECNALUBMA 

Program 2: Udskriv bagsiden af ​​en streng uden at bruge biblioteksfunktionen

Lad os overveje et eksempel for at udskrive bagsiden af ​​en streng ved hjælp af en brugerdefineret funktion.

Program2.c

 #include #include // function definition of the revstr() void revstr(char *str1) { // declare variable int i, len, temp; len = strlen(str1); // use strlen() to get the length of str string // use for loop to iterate the string for (i = 0; i <len 2; i++) { temp variable use to temporary hold the string str1[i]="str1[len" - i 1]; str1[len 1]="temp;" } int main() char str[50]; size of printf (' enter string: '); gets(str); gets() function take 
 before reversing %s 
', str); call revstr() revstr(str); after %s', < pre> <p> <strong>Output</strong> </p> <pre> Enter the string: Welcome Friends Before reversing the string: Welcome Friends After reversing the string: sdneirF emocleW </pre> <h3>Program 3: Print the reverse of a string using the recursion function</h3> <p>Let&apos;s consider an example to print the reverse of a string using the recursion function.</p> <p> <strong>Recursion function:</strong> A recursion function is a function that continuously calls the same function without using a looping statement.</p> <p> <strong>Program3.c</strong> </p> <pre> #include #include // use recursion function void revstr(char *str1) { // declare static variable static int i, len, temp; len = strlen(str1); // use strlen() to get the length of str string if (i <len 2){ temp variable use to temporary hold the string str1[i]="str1[len" - i 1]; str1[len 1]="temp;" i++; revstr(str1); recusively calls revstr() function } int main() { char str1[50]; size of printf (' enter string: '); gets(str1); gets() take 
 before reversing %s 
', str1); call after %s', < pre> <p> <strong>Output</strong> </p> <pre> Enter the string: LIFE INSURANCE Before reversing the string: LIFE INSURANCE After reversing the string: ECNARUSNI EFIL </pre> <h3>Program 4: Print the reverse of a string using for loop</h3> <p>Let&apos;s consider an example to print the reverse of a string using for loop in C programming language.</p> <p> <strong>Program4.c</strong> </p> <pre> #include #include #include void main() { char str[50], temp; // define the size of str[] array int i, left, right, len; printf (&apos; 
 Display a reverse string in the C: 
&apos;); printf (&apos; ----------------------- &apos;); printf (&apos; 
 Enter a string to reverse order: &apos;); scanf( &apos;%s&apos;, &amp;str); len = strlen(str); // get the length of the string left = 0; // set left index at 0 right = len - 1; // set right index len - 1 // use for loop to store the reverse string for (i = left; i <right; i++) { temp="str[i];" str[i]="str[right];" str[right]="temp;" right--; } printf (' the reverse of original string is: %s ', str); getch(); < pre> <p> <strong>Output</strong> </p> <pre> Display a reverse string in the C: ----------------------- Enter a string to reverse order: APPLE The reverse of the original string is: ELPPA </pre> <h3>Program 5: Print the reverse of a string using while loop</h3> <p>Let&apos;s consider an example to print the reverse of a string using while loop in C programming language.</p> <p> <strong>Program5.c</strong> </p> <pre> #include #include int main() { char str1[50], temp; // declare and initialize the size of string array. int i = 0, j =0; printf (&apos; Enter a string to be reversed: &apos;); scanf( &apos;%s&apos;, str1); j = strlen (str1) - 1; // get the length of the string // use while loop to define the condition while ( i <j) 1 { use temp variable to store the characters of str1 str1[j]="str1[i];" str1[i]="temp;" i++; i incremented by j--; j is decremented } printf (' reversed string: %s', str1); return 0; < pre> <p> <strong>Output</strong> </p> <pre> Enter a string to be reversed: JAVATPOINT The reversed of the string: TNIOPTAVAJ </pre> <h3>Program 6: Print the reverse of a string using pointers</h3> <p>Let&apos;s consider an example to print the reverse of a string using pointers in the C programming language.</p> <p> <strong>Program6.c</strong> </p> <pre> #include #include int str_len( char *st); void revstr( char *st); int main() { char st[50]; printf (&apos; Enter a string to be reversed: &apos;); scanf( &apos;%s&apos;, st); revstr(st); printf (&apos; The reverse string is: %s&apos;, st); return 0; } void revstr (char *st) { int len, i; char *start, *end, temp; len = str_len (st); start = st; end = st; for (i = 0; i <len - 1; i++) end++; for (i="0;" i < len 2; { temp="*end;" *end="*start;" *start="temp;" start++; end--; } int str_len (char *ptr) while ( *(ptr + i) !="" ) i++; return i; pre> <p> <strong>Output</strong> </p> <pre> Enter a string to be reversed: JAVATPOINT The reverse string is: TNIOPTAVAJ </pre> <h3>Program 7: Program to check whether the reverse string is a Palindrome</h3> <p>Consider a program to check whether the given string is a palindrome or not in the C programming language.</p> <p> <strong>Program7.c</strong> </p> <pre> #include #include int main () { // declare variables char str1[30]; int i, len, flag = 0; printf (&apos; Enter a string: &apos;); scanf (&apos;%s&apos;, str1); len = strlen( str1 ); // get the string length for ( i = 0; i <len; i++) { str1[i] is not equal to str1[len-i-1] if (str1[i] !="str1[len" - i 1]) flag="1;" break; exit from statement } (flag) printf (' %s a palindrome string', str1); else palindrome', return 0; < pre> <p> <strong>Output</strong> </p> <pre> Enter a string: madam madam is a palindrome string. </pre> <hr></len;></pre></len></pre></j)></pre></right;></pre></len></pre></len>

Program 3: Udskriv bagsiden af ​​en streng ved hjælp af rekursionsfunktionen

Lad os overveje et eksempel for at udskrive bagsiden af ​​en streng ved hjælp af rekursionsfunktionen.

Rekursionsfunktion: En rekursionsfunktion er en funktion, der kontinuerligt kalder den samme funktion uden at bruge en looping-sætning.

c++ par

Program3.c

 #include #include // use recursion function void revstr(char *str1) { // declare static variable static int i, len, temp; len = strlen(str1); // use strlen() to get the length of str string if (i <len 2){ temp variable use to temporary hold the string str1[i]="str1[len" - i 1]; str1[len 1]="temp;" i++; revstr(str1); recusively calls revstr() function } int main() { char str1[50]; size of printf (\' enter string: \'); gets(str1); gets() take 
 before reversing %s 
\', str1); call after %s\', < pre> <p> <strong>Output</strong> </p> <pre> Enter the string: LIFE INSURANCE Before reversing the string: LIFE INSURANCE After reversing the string: ECNARUSNI EFIL </pre> <h3>Program 4: Print the reverse of a string using for loop</h3> <p>Let&apos;s consider an example to print the reverse of a string using for loop in C programming language.</p> <p> <strong>Program4.c</strong> </p> <pre> #include #include #include void main() { char str[50], temp; // define the size of str[] array int i, left, right, len; printf (&apos; 
 Display a reverse string in the C: 
&apos;); printf (&apos; ----------------------- &apos;); printf (&apos; 
 Enter a string to reverse order: &apos;); scanf( &apos;%s&apos;, &amp;str); len = strlen(str); // get the length of the string left = 0; // set left index at 0 right = len - 1; // set right index len - 1 // use for loop to store the reverse string for (i = left; i <right; i++) { temp="str[i];" str[i]="str[right];" str[right]="temp;" right--; } printf (\' the reverse of original string is: %s \', str); getch(); < pre> <p> <strong>Output</strong> </p> <pre> Display a reverse string in the C: ----------------------- Enter a string to reverse order: APPLE The reverse of the original string is: ELPPA </pre> <h3>Program 5: Print the reverse of a string using while loop</h3> <p>Let&apos;s consider an example to print the reverse of a string using while loop in C programming language.</p> <p> <strong>Program5.c</strong> </p> <pre> #include #include int main() { char str1[50], temp; // declare and initialize the size of string array. int i = 0, j =0; printf (&apos; Enter a string to be reversed: &apos;); scanf( &apos;%s&apos;, str1); j = strlen (str1) - 1; // get the length of the string // use while loop to define the condition while ( i <j) 1 { use temp variable to store the characters of str1 str1[j]="str1[i];" str1[i]="temp;" i++; i incremented by j--; j is decremented } printf (\' reversed string: %s\', str1); return 0; < pre> <p> <strong>Output</strong> </p> <pre> Enter a string to be reversed: JAVATPOINT The reversed of the string: TNIOPTAVAJ </pre> <h3>Program 6: Print the reverse of a string using pointers</h3> <p>Let&apos;s consider an example to print the reverse of a string using pointers in the C programming language.</p> <p> <strong>Program6.c</strong> </p> <pre> #include #include int str_len( char *st); void revstr( char *st); int main() { char st[50]; printf (&apos; Enter a string to be reversed: &apos;); scanf( &apos;%s&apos;, st); revstr(st); printf (&apos; The reverse string is: %s&apos;, st); return 0; } void revstr (char *st) { int len, i; char *start, *end, temp; len = str_len (st); start = st; end = st; for (i = 0; i <len - 1; i++) end++; for (i="0;" i < len 2; { temp="*end;" *end="*start;" *start="temp;" start++; end--; } int str_len (char *ptr) while ( *(ptr + i) !="" ) i++; return i; pre> <p> <strong>Output</strong> </p> <pre> Enter a string to be reversed: JAVATPOINT The reverse string is: TNIOPTAVAJ </pre> <h3>Program 7: Program to check whether the reverse string is a Palindrome</h3> <p>Consider a program to check whether the given string is a palindrome or not in the C programming language.</p> <p> <strong>Program7.c</strong> </p> <pre> #include #include int main () { // declare variables char str1[30]; int i, len, flag = 0; printf (&apos; Enter a string: &apos;); scanf (&apos;%s&apos;, str1); len = strlen( str1 ); // get the string length for ( i = 0; i <len; i++) { str1[i] is not equal to str1[len-i-1] if (str1[i] !="str1[len" - i 1]) flag="1;" break; exit from statement } (flag) printf (\' %s a palindrome string\', str1); else palindrome\', return 0; < pre> <p> <strong>Output</strong> </p> <pre> Enter a string: madam madam is a palindrome string. </pre> <hr></len;></pre></len></pre></j)></pre></right;></pre></len>

Program 4: Udskriv bagsiden af ​​en streng med for loop

Lad os overveje et eksempel for at udskrive bagsiden af ​​en streng ved at bruge for loop i programmeringssproget C.

Program4.c

 #include #include #include void main() { char str[50], temp; // define the size of str[] array int i, left, right, len; printf (' 
 Display a reverse string in the C: 
'); printf (' ----------------------- '); printf (' 
 Enter a string to reverse order: &apos;); scanf( &apos;%s&apos;, &amp;str); len = strlen(str); // get the length of the string left = 0; // set left index at 0 right = len - 1; // set right index len - 1 // use for loop to store the reverse string for (i = left; i <right; i++) { temp="str[i];" str[i]="str[right];" str[right]="temp;" right--; } printf (\' the reverse of original string is: %s \', str); getch(); < pre> <p> <strong>Output</strong> </p> <pre> Display a reverse string in the C: ----------------------- Enter a string to reverse order: APPLE The reverse of the original string is: ELPPA </pre> <h3>Program 5: Print the reverse of a string using while loop</h3> <p>Let&apos;s consider an example to print the reverse of a string using while loop in C programming language.</p> <p> <strong>Program5.c</strong> </p> <pre> #include #include int main() { char str1[50], temp; // declare and initialize the size of string array. int i = 0, j =0; printf (&apos; Enter a string to be reversed: &apos;); scanf( &apos;%s&apos;, str1); j = strlen (str1) - 1; // get the length of the string // use while loop to define the condition while ( i <j) 1 { use temp variable to store the characters of str1 str1[j]="str1[i];" str1[i]="temp;" i++; i incremented by j--; j is decremented } printf (\' reversed string: %s\', str1); return 0; < pre> <p> <strong>Output</strong> </p> <pre> Enter a string to be reversed: JAVATPOINT The reversed of the string: TNIOPTAVAJ </pre> <h3>Program 6: Print the reverse of a string using pointers</h3> <p>Let&apos;s consider an example to print the reverse of a string using pointers in the C programming language.</p> <p> <strong>Program6.c</strong> </p> <pre> #include #include int str_len( char *st); void revstr( char *st); int main() { char st[50]; printf (&apos; Enter a string to be reversed: &apos;); scanf( &apos;%s&apos;, st); revstr(st); printf (&apos; The reverse string is: %s&apos;, st); return 0; } void revstr (char *st) { int len, i; char *start, *end, temp; len = str_len (st); start = st; end = st; for (i = 0; i <len - 1; i++) end++; for (i="0;" i < len 2; { temp="*end;" *end="*start;" *start="temp;" start++; end--; } int str_len (char *ptr) while ( *(ptr + i) !="" ) i++; return i; pre> <p> <strong>Output</strong> </p> <pre> Enter a string to be reversed: JAVATPOINT The reverse string is: TNIOPTAVAJ </pre> <h3>Program 7: Program to check whether the reverse string is a Palindrome</h3> <p>Consider a program to check whether the given string is a palindrome or not in the C programming language.</p> <p> <strong>Program7.c</strong> </p> <pre> #include #include int main () { // declare variables char str1[30]; int i, len, flag = 0; printf (&apos; Enter a string: &apos;); scanf (&apos;%s&apos;, str1); len = strlen( str1 ); // get the string length for ( i = 0; i <len; i++) { str1[i] is not equal to str1[len-i-1] if (str1[i] !="str1[len" - i 1]) flag="1;" break; exit from statement } (flag) printf (\' %s a palindrome string\', str1); else palindrome\', return 0; < pre> <p> <strong>Output</strong> </p> <pre> Enter a string: madam madam is a palindrome string. </pre> <hr></len;></pre></len></pre></j)></pre></right;>

Program 5: Udskriv bagsiden af ​​en streng med while-løkke

Lad os overveje et eksempel for at udskrive bagsiden af ​​en streng ved at bruge while-løkke i programmeringssproget C.

Program 5.c

 #include #include int main() { char str1[50], temp; // declare and initialize the size of string array. int i = 0, j =0; printf (&apos; Enter a string to be reversed: &apos;); scanf( &apos;%s&apos;, str1); j = strlen (str1) - 1; // get the length of the string // use while loop to define the condition while ( i <j) 1 { use temp variable to store the characters of str1 str1[j]="str1[i];" str1[i]="temp;" i++; i incremented by j--; j is decremented } printf (\' reversed string: %s\', str1); return 0; < pre> <p> <strong>Output</strong> </p> <pre> Enter a string to be reversed: JAVATPOINT The reversed of the string: TNIOPTAVAJ </pre> <h3>Program 6: Print the reverse of a string using pointers</h3> <p>Let&apos;s consider an example to print the reverse of a string using pointers in the C programming language.</p> <p> <strong>Program6.c</strong> </p> <pre> #include #include int str_len( char *st); void revstr( char *st); int main() { char st[50]; printf (&apos; Enter a string to be reversed: &apos;); scanf( &apos;%s&apos;, st); revstr(st); printf (&apos; The reverse string is: %s&apos;, st); return 0; } void revstr (char *st) { int len, i; char *start, *end, temp; len = str_len (st); start = st; end = st; for (i = 0; i <len - 1; i++) end++; for (i="0;" i < len 2; { temp="*end;" *end="*start;" *start="temp;" start++; end--; } int str_len (char *ptr) while ( *(ptr + i) !="" ) i++; return i; pre> <p> <strong>Output</strong> </p> <pre> Enter a string to be reversed: JAVATPOINT The reverse string is: TNIOPTAVAJ </pre> <h3>Program 7: Program to check whether the reverse string is a Palindrome</h3> <p>Consider a program to check whether the given string is a palindrome or not in the C programming language.</p> <p> <strong>Program7.c</strong> </p> <pre> #include #include int main () { // declare variables char str1[30]; int i, len, flag = 0; printf (&apos; Enter a string: &apos;); scanf (&apos;%s&apos;, str1); len = strlen( str1 ); // get the string length for ( i = 0; i <len; i++) { str1[i] is not equal to str1[len-i-1] if (str1[i] !="str1[len" - i 1]) flag="1;" break; exit from statement } (flag) printf (\' %s a palindrome string\', str1); else palindrome\', return 0; < pre> <p> <strong>Output</strong> </p> <pre> Enter a string: madam madam is a palindrome string. </pre> <hr></len;></pre></len></pre></j)>

Program 6: Udskriv bagsiden af ​​en streng ved hjælp af pegepinde

Lad os overveje et eksempel på at udskrive bagsiden af ​​en streng ved hjælp af pointere i programmeringssproget C.

10 af 100,00

Program 6.c

 #include #include int str_len( char *st); void revstr( char *st); int main() { char st[50]; printf (&apos; Enter a string to be reversed: &apos;); scanf( &apos;%s&apos;, st); revstr(st); printf (&apos; The reverse string is: %s&apos;, st); return 0; } void revstr (char *st) { int len, i; char *start, *end, temp; len = str_len (st); start = st; end = st; for (i = 0; i <len - 1; i++) end++; for (i="0;" i < len 2; { temp="*end;" *end="*start;" *start="temp;" start++; end--; } int str_len (char *ptr) while ( *(ptr + i) !="" ) i++; return i; pre> <p> <strong>Output</strong> </p> <pre> Enter a string to be reversed: JAVATPOINT The reverse string is: TNIOPTAVAJ </pre> <h3>Program 7: Program to check whether the reverse string is a Palindrome</h3> <p>Consider a program to check whether the given string is a palindrome or not in the C programming language.</p> <p> <strong>Program7.c</strong> </p> <pre> #include #include int main () { // declare variables char str1[30]; int i, len, flag = 0; printf (&apos; Enter a string: &apos;); scanf (&apos;%s&apos;, str1); len = strlen( str1 ); // get the string length for ( i = 0; i <len; i++) { str1[i] is not equal to str1[len-i-1] if (str1[i] !="str1[len" - i 1]) flag="1;" break; exit from statement } (flag) printf (\' %s a palindrome string\', str1); else palindrome\', return 0; < pre> <p> <strong>Output</strong> </p> <pre> Enter a string: madam madam is a palindrome string. </pre> <hr></len;></pre></len>

Program 7: Program til at kontrollere, om den omvendte streng er en palindrom

Overvej et program til at kontrollere, om den givne streng er et palindrom eller ej i programmeringssproget C.

Program7.c

 #include #include int main () { // declare variables char str1[30]; int i, len, flag = 0; printf (&apos; Enter a string: &apos;); scanf (&apos;%s&apos;, str1); len = strlen( str1 ); // get the string length for ( i = 0; i <len; i++) { str1[i] is not equal to str1[len-i-1] if (str1[i] !="str1[len" - i 1]) flag="1;" break; exit from statement } (flag) printf (\\' %s a palindrome string\\', str1); else palindrome\\', return 0; < pre> <p> <strong>Output</strong> </p> <pre> Enter a string: madam madam is a palindrome string. </pre> <hr></len;>