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_backconst 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 << ":\n";        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;}