LightOJ 1112 Curious Robin Hood （单点更新+区间求和）

#include<stdio.h>
#include<string.h>
#include<queue>
#include<algorithm>
#define N 100010
#define Lson root<<1, L, tree[root].Mid()
#define Rson root<<1|1, tree[root].Mid() + 1, R

using namespace std;

struct Tree
{
    int L, R;
    long long sum, e;
    bool op;
    int Mid()
    {
        return (R + L) / 2;
    }
} tree[N * 4];

long long al[N];

void Build(int root, int L, int R)
{
    tree[root].L = L, tree[root].R = R;
    tree[root].op = false;
    if(L == R)
    {
        tree[root].sum = al[L];
        return ;
    }

    Build(Lson);
    Build(Rson);

    tree[root].sum = tree[root<<1].sum + tree[root<<1|1].sum;
}

void Insert(int root, int k, long long e)
{
    tree[root].sum += e;
    if(tree[root].L == tree[root].R)
        return ;
    if(k <= tree[root].Mid())
        Insert(root<<1, k, e);
    else if(k > tree[root].Mid())
        Insert(root<<1|1, k, e);
}

long long Query(int root, int L, int R)
{
    if(tree[root].L == L && tree[root].R == R)
        return tree[root].sum;
    if(R <= tree[root].Mid())
        return Query(root<<1, L, R);
    else if(L > tree[root].Mid())
        return Query(root<<1|1, L, R);
    else
        return Query(Lson) + Query(Rson);
}

int main()
{
    int m, n, a, p, b, i, t, x = 0;
    long long e;
    char s[10];
    scanf("%d", &t);
    while(t--)
    {
        x++;
        scanf("%d%d", &m, &n);
        for(i = 1 ; i <= m ; i++)
            scanf("%lld", &al[i]);
        Build(1, 1, m);
        printf("Case %d:\n", x);
        while(n--)
        {
            scanf("%d", &p);
            if(p == 1)
            {
                scanf("%d", &a);
                printf("%d\n", Query(1, a + 1, a + 1));//注意! ! ! 坑来了！！！
                Insert(1, a + 1, -Query(1, a + 1, a + 1));//此处一样
            }
            else if(p == 2)
            {
                scanf("%d%d", &a, &b);
                Insert(1, a + 1, b);
            }
            else if(p == 3)
            {
                scanf("%d%d", &a, &b);
                printf("%lld\n", Query(1, a + 1, b + 1));
            }
        }
    }
    return 0;
}