#include <stdio.h>

#include <stdlib.h>

​

char str[100], pat[100], rep[100], ans[100];

int i, j, m, c, k, flag;

​

void strs() {

    flag = 0; // Reset flag

    while (str[c] != '\0') {

        if (str[m] == pat[i]) {

            i++;

            m++;

            if (pat[i] == '\0') {

                flag = 1;

                for (k = 0; rep[k] != '\0'; k++, j++) {

                    ans[j] = rep[k];

                }

                i = 0;

                c = m;

            }

        } else {

            ans[j] = str[c];

            j++;

            c++;

            m = c;

            i = 0;

        }

    }

    ans[j] = '\0';

}

​

int main() {

    printf("Enter the string:\n");

    fgets(str, sizeof(str), stdin);

​

    printf("Enter the pattern:\n");

    fgets(pat, sizeof(pat), stdin);

​

    printf("Enter the replacement:\n");

    fgets(rep, sizeof(rep), stdin);

​

    i = j = m = c = 0; // Reset variables

    strs();

​

    if (flag == 1) {

        printf("Result: %s", ans);

    } else {

        printf("Pattern not found in the string.");

    }

​

    return 0;

}