hdu1166-敌兵布阵

题意：

读入一个数组，完成单点加，单点减，和区间求和三种操作。

解法：

明摆着的一颗线段树，SB题。

CODE:

#pragma GCC optimize(2)
#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>

using namespace std;

#define LL long long
#define N 100010

struct Tree {
    int lson,rson;
    int sum,tag;
}tree[N * 2];

int n,cnt = 1,a[N],ans,T,test;
char s[N];

inline int read(){
    int 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 << 1) + (x << 3) + (ch ^ 48);ch = getchar();}
    return x * f;
}
inline void pushup(int x) {
    tree[x].sum = tree[tree[x].lson].sum + tree[tree[x].rson].sum;
}
inline void pushdown(int x,int l,int r) {
    int mid = (l + r) >> 1;
    tree[tree[x].lson].sum += (mid - l + 1) * tree[x].tag;
    tree[tree[x].lson].tag += tree[x].tag;
    tree[tree[x].rson].sum += (r - mid) * tree[x].tag;
    tree[tree[x].rson].tag += tree[x].tag;
    tree[x].tag = 0;
}
void build(int x,int l,int r) {
    if(l == r) {
        tree[x].sum = a[l];
        return;
    }
    int mid = (l + r) >> 1;
    tree[x].lson = ++cnt;
    build(tree[x].lson,l,mid);
    tree[x].rson = ++cnt;
    build(tree[x].rson,mid+1,r);
    pushup(x);
}
void update(int x,int l,int r,int k,int v) {
    if(l == r) {
        tree[x].sum += v;
        return;
    }
    int mid = (l + r) >> 1;
    if(k <= mid) update(tree[x].lson,l,mid,k,v);
    else update(tree[x].rson,mid+1,r,k,v);
    pushup(x);
}
int query(int x,int l,int r,int ll,int rr) {
    if(l == ll && r == rr) return tree[x].sum;
    int mid = (l + r) >> 1;
    pushdown(x,l,r);
    if(rr <= mid) return query(tree[x].lson,l,mid,ll,rr);
    else if(ll > mid) return query(tree[x].rson,mid+1,r,ll,rr);
    else return query(tree[x].lson,l,mid,ll,mid) + query(tree[x].rson,mid+1,r,mid+1,rr);
}

int main() {
    T = read();
    while(T--) {
        test++;
        n = read();
        for(int i = 1 ; i <= n ; i++)
            a[i] = read();
        build(1,1,n);
        printf("Case %d:\n",test);
        while(true) {
            scanf("%s",s+1);
            if(s[1] == 'E') break;
            if(s[1] == 'A') {
                int i = read() , j = read();
                update(1,1,n,i,j);
            }
            if(s[1] == 'S') {
                int i = read() , j = read();
                update(1,1,n,i,-j);
            }
            if(s[1] == 'Q') {
                int i = read() , j = read();
                printf("%d\n",query(1,1,n,i,j));
            }
        }
    }
    //system("pause");
    return 0;
}