HDU 1166 敌兵布阵 线段树

题目链接:

http://acm.hdu.edu.cn/showproblem.php?pid=1166

题意:

题解:

代码:

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define MS(a) memset(a,0,sizeof(a))
#define MP make_pair
#define PB push_back
const int INF = 0x3f3f3f3f;
const ll INFLL = 0x3f3f3f3f3f3f3f3fLL;
inline ll read(){
    ll x=0,f=1;char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
    while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
    return x*f;
}
//////////////////////////////////////////////////////////////////////////
const int maxn = 5e4+10;

int sum[maxn<<2];

void pushup(int rt){
    sum[rt] = sum[rt<<1]+sum[rt<<1|1];
}

void build(int l,int r,int rt){
    if(l == r){
        sum[rt] = read();
        return ;
    }
    int mid = (l+r)/2;
    build(l,mid,rt<<1);
    build(mid+1,r,rt<<1|1);
    pushup(rt);
}

void update(int p,int add,int l,int r,int rt){

    if(l==r){
        sum[rt] += add;
        return ;
    }
    int mid = (l+r)/2;
    if(p <= mid)
        update(p,add,l,mid,rt<<1);
    else
        update(p,add,mid+1,r,rt<<1|1);
    pushup(rt);
}

int query(int L,int R,int l,int r,int rt){
    if(L<=l && r<=R){
        return sum[rt];
    }
    int mid = (l+r)/2;
    int ans = 0;
    if(L>mid){
        ans += query(L,R,mid+1,r,rt<<1|1);
    }
    else if(R<=mid){
        ans += query(L,R,l,mid,rt<<1);
    }else{
        ans += query(L,R,l,mid,rt<<1) + query(L,R,mid+1,r,rt<<1|1);
    }
    return ans;
}

int main(){
    int T=read();
    for(int cas=1; cas<=T; cas++){
        cout << "Case " << cas << ":
";
        int n = read();
        build(1,n,1);
        char op[10];
        while(scanf("%s",op) && op[0]!='E'){
            int a=read(),b=read();
            if(op[0]=='Q')
                cout << query(a,b,1,n,1) << endl;
            else if(op[0]=='S')
                update(a,-b,1,n,1);
            else 
                update(a,b,1,n,1);
        }
    }

    return 0;
}