#include <stdio.h>
 
int main() {
    char str1[100], str2[100];
    int i = 0, j = 0;
 
    // Input first string
    printf("Enter the first string: ");
    gets(str1); // unsafe, use fgets() in practice
 
    // Input second string
    printf("Enter the second string: ");
    gets(str2);
 
    // Move to the end of the first string
    while (str1[i] != '\0') {
        i++;
    }
 
    // Copy second string to the end of first string
    while (str2[j] != '\0') {
        str1[i] = str2[j];
        i++;
        j++;
    }
 
    // Add null terminator
    str1[i] = '\0';
 
    // Display concatenated string
    printf("Concatenated string: %s\n", str1);
 
    return 0;
}

#include <stdio.h>
 
int main() {
    char str1[100], str2[100];
    int i = 0, j = 0;
 
    printf("Enter the first string: ");
    fgets(str1, sizeof(str1), stdin);
 
    printf("Enter the second string: ");
    fgets(str2, sizeof(str2), stdin);
 
    // Remove newline characters (if present)
    while (str1[i] != '\0') {
        if (str1[i] == '\n') str1[i] = '\0';
        i++;
    }
 
    while (str2[j] != '\0' && str2[j] != '\n') {
        str1[i++] = str2[j++];
    }
 
    str1[i] = '\0';
 
    printf("Concatenated string: %s\n", str1);
 
    return 0;
}