HDU 1166 敌兵布阵

单调更新区间查询和

#include <map>
#include <set>
#include <list>
#include <cmath>
#include <ctime>
#include <deque>
#include <stack>
#include <queue>
#include <cctype>
#include <cstdio>
#include <string>
#include <vector>
#include <climits>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <algorithm>
#define LL long long
#define PI 3.1415926535897932626
using namespace std;
int gcd(int a, int b) {return a % b == 0 ? b : gcd(b, a % b);}
const int MAXN = 50010;
const int INF = 0x3f3f3f3f;
struct node
{
    int l,r;
    int sum;
}tree[MAXN * 4];
int src[MAXN];

void build(int id,int l,int r)
{
    tree[id].l = l;
    tree[id].r = r;
    if (l == r)
    {
        tree[id].sum = src[l];
        return;
    }
    int mid = (l + r) / 2;
    build(id * 2,l,mid);
    build(id * 2 + 1,mid + 1,r);
    tree[id].sum = tree[id * 2].sum + tree[id * 2 + 1].sum;
}

void update(int id,int pos,int val)
{
    if (tree[id].l == pos && tree[id].r == pos)
    {
        tree[id].sum += val;
        return;
    }
    int mid = (tree[id].l + tree[id].r) / 2;
    if (pos <= mid) update(id * 2,pos,val);
    else update(id * 2 + 1,pos,val);
    tree[id].sum = tree[id * 2].sum + tree[id * 2 + 1].sum;
}

int query(int id,int l,int r)
{
    if (tree[id].l >= l && tree[id].r <= r)
    {
        return tree[id].sum;
    }
    int mid = (tree[id].l + tree[id].r) / 2;
    if (l > mid) return query(id * 2 + 1,l,r);
    else if (r <= mid) return query(id * 2,l,r);
    else
    {
        return query(id * 2 ,l,mid) + query(id * 2 + 1,mid + 1,r);
    }
}

int main()
{
    int T,kase = 1;
    scanf("%d",&T);
    while (T--)
    {
        int N;
        scanf("%d",&N);
        for (int i = 1 ; i <= N ; i++) scanf("%d",&src[i]);
        build(1,1,N);
        printf("Case %d:\n",kase++);
        char op[10];
        while(scanf("%s",op) != EOF)
        {
            if (op[0] == 'E') break;
            if (op[0] == 'Q')
            {
                int l,r;
                scanf("%d%d",&l,&r);
                printf("%d\n",query(1,l,r));
            }
            if (op[0] == 'A')
            {
                int x,val;
                scanf("%d%d",&x,&val);
                update(1,x,val);
            }
            if(op[0] == 'S')
            {
                int x,val;
                scanf("%d%d",&x,&val);
                update(1,x,-val);
            }
        }
    }
    return 0;
}
View Code

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