12930 - Number String Process

#include <stdio.h>

char buf[1005];
long long int total = 0;

void take_num(int a, int b, int sz, int length){
    long long int numA = 0;
    long long int numB = 0;
    total = 0;
    // take numB and remove b first, because it is easier to remove it
    for(int i = b; i < length; i++){
        if (i < b + sz){
            numB = numB*10 + (buf[i] - '0');
            //printf("numB = %d, i = %d, buf[i] = %c\n", numB, i, buf[i]);
        }
    }
    // remove
    for(int i = b; i < length - sz; i++){
        buf[i] = buf[i + sz];
        //printf("%c", buf[i]);
    }
    //printf("\n");
    length = length - sz;
    //continue this
    for(int i = a; i < length; i++){
        if (i < a + sz){
            // parse
            numA = numA*10 + (buf[i] - '0');
            //printf("numA = %d, i = %d, buf[i] = %c\n", numA, i, buf[i]);
        }
    }
    for(int i = a; i < length - sz; i++){
        buf[i] = buf[i+sz];
    }
    length = length - sz;
    /*for(int i = 0; i < length; i++){
        printf("%c", buf[i]);
    }*/
    total = numA * numB;
    return;
}

int main(){
    int length;
    scanf("%d", &length);
    scanf("%s", buf);
    /*for(int i = 0; i < length; i++){
        printf("%c ", buf[i]);
    }*/
    int q;
    scanf("%d", &q);
    while(q--){
        int a, b, sz;
        scanf("%d %d %d", &a, &b, &sz);
        take_num(a, b, sz, length);
        // make a function where the string size decresse in size and everything
        printf("%lld\n", total);

    }
    return 0;
}