#include <stdio.h>
int main() {
    char list[] = "22QPP1";
    const char *pa, *pb;
    char *pc, *pd;
    pa = &list[1];
    list[2] = 'K';
    pb = &list[3];
    pc = list;
    pd = strstr(pa, pb);
    printf("pd: %s \n", pd);
    if (pd != 0) {
        strncpy(pd, "77", 3);
        printf("pc: %s \n", pc);
    }
    printf("pb: %s \n", pb);
    return 0;      
}