//Program to delete the characters from string1 which are present in string2:

#include <stdio.h>
#include <string.h>

void delete_chars(char *string1, char *string2) {
    int len1 = strlen(string1);
    int len2 = strlen(string2);
    int map[256] = {0};
    for (int i = 0; i < len2; i++) {
        map[string2[i]] = 1;
    }
    int index = 0;
    for (int i = 0; i < len1; i++) {
        if (map[string1[i]] == 0) {
            string1[index++] = string1[i];
        }
    }
    string1[index] = '\0';
}

int main() {
    char string1[] = "whatsapp";
    char string2[] = "wat";
    printf("String1: %s\n", string1);
    printf("String2: %s\n", string2);
    delete_chars(string1, string2);
    printf("After deleting characters from string2 in string1: %s\n", string1);
    return 0;
}