boj5676.cpp

#include <iostream>
#include <cstdio>
using namespace std;
#define MAXN 100005
int N, K, indexTree[4*MAXN], arr[MAXN], p;
void init(){
    p = 1;
    while(p < N) p <<= 1;
    for(int i = 0 ; i < N ; i++)
        indexTree[p+i] = arr[i];
    for(int i = p-1 ; i >=1 ; i--)
        indexTree[i] = indexTree[i*2] * indexTree[i*2+1];
}
void update(int index, int value){
    index += p-1;
    indexTree[index] = value;
    for(int i = (index >> 1); i >= 1; i >>= 1)
        indexTree[i] = indexTree[i*2]*indexTree[i*2+1];
}
int find(int left, int right){
    left += p-1;
    right += p-1;
    int ans = 1;
    while(left <= right){
        if(left & 1){
            ans *= indexTree[left];
            left++;
        }
        if(!(right & 1)){
            ans *= indexTree[right];
            right--;
        }
        left >>=1 ,right >>=1;
    }
    return ans;
}
int trans(int a){
    if(a>0)
        return 1;
    else if(a==0)
        return 0;
    else
        return -1;
}
int main(){
    while(scanf("%d%d", &N, &K) != EOF){
        for(int i = 0 ; i < N ; i++){
            scanf("%d", &arr[i]);
            arr[i] = trans(arr[i]);
        }
        init();
        for(int i = 1 ; i<= K ; i++){
            char T;
            int a, b;
            scanf("\n%c%d%d", &T, &a, &b);
            if(T == 'C'){
                update(a, trans(b));
            }else{
                int ans = find(a, b);
                if(ans > 0)
                    printf("+");
                else if(ans == 0)
                    printf("0");
                else
                    printf("-");
            }
        }
        printf("\n");
    }
    return 0;
}