HDU 1166 敵兵佈陣 【簡單的樹狀數組||線段樹】

【解題思路】

直接樹狀數組過

【代碼】

#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<algorithm>
#include<cmath>
#include<ctime>
#include<cstring>
#include<string>
#include<cctype>
#include<iomanip>
#define LL long long
//#define LOCAL
#define lowbit(i) (i&(-i))
using namespace std;

const int N=50011;
int tree[N];
int T;
char ch[6];
int Case=0;

void Add(int pos,int val){
	while (pos<=N){
		tree[pos]+=val;
		pos+=lowbit(pos);
	}
}

int Query(int pos){
	int zjl=0;
	while (pos>0){
		zjl+=tree[pos];
		pos-=lowbit(pos);
	}
	return zjl;
}

int main(){
#ifdef LOCAL
    freopen("HDU1166.in","r",stdin);
#endif
	scanf("%d",&T);
	while (T--){
		Case++;
		printf("Case %d:\n",Case);
		memset(tree,0,sizeof(tree));
		int n;
		scanf("%d",&n);
		for (int i=1;i<=n;++i){
			int a;
		    scanf("%d",&a);
		    Add(i,a);
		}
		while (scanf("%s",&ch[0])&&ch[0]!='E'){
			if (ch[0]=='A'){
				int x,y;
				scanf("%d%d",&x,&y);
				Add(x,y);
			}
			else if (ch[0]=='S'){
				int x,y;
				scanf("%d%d",&x,&y);
				Add(x,-y);
			}
			else if (ch[0]=='Q'){
				int x,y;
				scanf("%d%d",&x,&y);
				printf("%d\n",Query(y)-Query(x-1));
			}
		}
	}
	return 0;
}