2016夏季练习——线段树

来源：POJ3468

成段更新

代码：

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#define lson rt<<1
#define rson rt<<1|1
using namespace std;
typedef long long LL;
const int MAXN = 111111;
LL tree[MAXN<<2];
LL lazy[MAXN<<2];
int dd;
int n,q;
char ch[5];
int x,y;
void pushup(int rt){
    tree[rt] = tree[lson] + tree[rson];
}
void pushdown(int rt,int m){
    if(lazy[rt]){
        tree[lson] += lazy[rt]*(m-(m>>1));
        tree[rson] += lazy[rt]*(m>>1);
        lazy[rson] += lazy[rt];
        lazy[lson] += lazy[rt];
        lazy[rt] = 0;
    }
}
void build(int rt,int l,int r){
    lazy[rt] = 0 ;
    if(l==r){
        scanf("%I64d",&tree[rt]);
        return ;
    }
    int mid = (l+r)>>1;
    build(lson,l,mid);
    build(rson,mid+1,r);
    pushup(rt);
}
void update(int rt,int l,int r,int left,int right,int data){
    if(left<=l && r<=right){
        tree[rt] += (LL)(r-l+1)*data;
        lazy[rt] += data;
        return ;
    }
    pushdown(rt,r-l+1);
    int mid = (l+r)>>1;
    if(left<=mid) update(lson,l,mid,left,right,data);
    if(right>mid) update(rson,mid+1,r,left,right,data);
    pushup(rt);
}
LL query(int rt,int l,int r,int left,int right){
    if(left<=l && r<=right) {
        return tree[rt];
    }
    pushdown(rt,r-l+1);
    int mid = (l+r)>>1;
    LL ans = 0;
    if(left<=mid) ans+=query(lson,l,mid,left,right);
    if(right>mid) ans+=query(rson,mid+1,r,left,right);
    return ans;
}
int main(){
    scanf("%d%d",&n,&q);
    //for(int i=1;i<=n;i++) scanf("%lld",&a[i]);
    build(1,1,n);
    //getchar();
    while(q--){
        scanf("%s",ch);
        if(ch[0] == 'Q'){
            scanf("%d%d",&x,&y);
            printf("%I64d\n",query(1,1,n,x,y));
        }
        if(ch[0] == 'C'){
            scanf("%d%d",&x,&y);
            scanf("%d",&dd);
            update(1,1,n,x,y,dd);
        }
    }
    return 0;
}