hdu 1166 敌兵布阵 (线段树)

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include <time.h>
#include <algorithm>

using namespace std;

const int N = 50005;

int num[N << 2];

void Update(int i){
    num[i] = num[i * 2] + num[i * 2 + 1];　　　　//更新父亲结点 
}

void Build(int left, int right, int i){　　　　//建树
    if(left == right){
        scanf("%d", &num[i]);
        return;
    }
    int mid = (left + right) / 2;
    Build(left, mid, i * 2);
    Build(mid + 1, right, i * 2 + 1);
    Update(i);
}

void Add(int loc, int number, int left, int right, int i){　　　　 //单点更新 
    if(left == right){
        num[i] += number;
        return;
    }
    int mid = (left + right) / 2;
    if(loc <= mid) Add(loc, number, left, mid, i * 2);
    else Add(loc, number, mid + 1, right, i * 2 + 1);
    Update(i);
}

int Query(int ll, int rr, int left, int right, int i){　　　　//线段查询 
    if(ll == left && rr == right) return num[i];
    int mid = (left + right) / 2;
    if(rr <= mid) return Query(ll, rr, left, mid, i * 2);
    else if(ll > mid) return Query(ll, rr, mid + 1, right, i * 2 + 1);
    else return Query(ll, mid, left, mid, i * 2) + Query(mid + 1, rr, mid + 1, right, i * 2 + 1);
}

int main(){
    int T, count = 1;
    scanf("%d", &T);
    while(T--){
        int n;
        scanf("%d", &n);
        printf("Case %d:\n", count++);
        Build(1, n, 1);
        while(1){
            char order[10];
            scanf("%s", order);
            if(order[0] == ‘E‘) break;
            int a, b;
            scanf("%d%d", &a, &b);
            if(order[0] == ‘A‘) Add(a, b, 1, n, 1);
            else if(order[0] == ‘S‘) Add(a, -b, 1, n, 1);
            else if(order[0] == ‘Q‘) printf("%d\n", Query(a, b, 1, n, 1));
        }
    }
　　return 0; 
}