Cod sursa(job #1425351)

Utilizator isa_mirica_mihaiMirica Matei isa_mirica_mihai Data 27 aprilie 2015 12:53:55
Problema Arbori indexati binar Scor 100
Compilator cpp Status done
Runda pregatire-lot-aib Marime 1.23 kb
#include <cstdio>
using namespace std;
int n, aib[150005];
void add(int a, int b){
    for (; a <= n; a += a & -a)
        aib[a] += b;
}
int sum(int a){
    int s = 0;
    for (;a; a -= a & -a)
        s += aib[a];
    return s;
}
int caut(int val){
    int i, poz;
    for (poz = 1; poz < n; poz <<= 1);
    for(i = 0; poz; poz /=  2){
         if(i + poz <= n){
            if(val >= aib[i + poz]){
                i += poz;
                val -= aib[i];
                if (val == 0)
                  return i;
            }
         }
    }
    return -1;
}
int main()
{
    freopen("aib.in", "r", stdin);
    freopen("aib.out", "w", stdout);
    int m, op, a, b, i;
    scanf("%d%d", &n, &m);
    for (i = 1; i <= n; i ++){
        scanf("%d", &a);
        add(i, a);
    }
    for (i = 1; i <= m; i ++){
        scanf("%d", &op);
        if (op == 0){
            scanf("%d%d", &a, &b);
            add(a, b);
        }
        else
            if (op == 1){
                scanf("%d%d", &a, &b);
                printf("%d\n", sum(b) - sum(a - 1));
            }
            else{
                scanf("%d", &a);
                printf("%d\n", caut(a));
            }
    }
    return 0;
}