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【POJ】A Simple Problem with Integers(线段树区间修增减求和)

线段树区间修改增加问题,模板题,注意懒惰处理。

134434492013010521003468Accepted4308K1610MSC++2362B2014-09-15 15:46:35

#include<cstdio>
#include<cstring>
#include<iostream>
#include<vector>
#include<queue>
#include<map>
#include<cstdlib>
#include<stack>
#include<set>
#include<string>
using namespace std;
typedef long long LL;
typedef unsigned long long ULL;
#define esp 1e-10
const int maxn = 100000 + 10;
#define MAXD 100
int n , m;
LL tree[maxn << 2];
LL mark[maxn << 2];
void BuildTree(int L,int R,int pos){
    if(L == R){
        scanf("%I64d",&tree[pos]);
        return ;
    }
    int m = (L + R) >> 1;
    BuildTree(L, m , pos << 1);
    BuildTree(m + 1, R , (pos << 1)|1);
    tree[pos] = tree[pos << 1] + tree[(pos << 1)|1];
    return ;
}
void UpDate(int l,int r,int add,int L,int R,int pos){
    if(l <= L && R <= r){
        mark[pos] += add;
        tree[pos] += add * (R - L + 1);
        return ;
    }
    int  m  = (L + R) >> 1;
    int len =  R - L + 1;
    if(mark[pos]){ //懒惰标记下移
        mark[pos << 1] += mark[pos];
        mark[(pos << 1)|1] += mark[pos];
        tree[pos << 1] += mark[pos] * (len - (len >> 1));
        tree[(pos << 1)|1] += mark[pos] * (len >> 1);
        mark[pos] = 0;
    }
    if(l <= m) UpDate(l,r,add,L,m,pos << 1);
    if(r >  m) UpDate(l,r,add,m + 1,R,(pos << 1)|1);
    tree[pos] = tree[pos << 1] + tree[(pos << 1)|1];
    return ;
}
LL Query(int l,int r,int L,int R,int pos){
    if(l <= L && R <= r){
        return tree[pos];
    }
    int   m = (L + R) >> 1;
    int len =  R - L + 1;
        if(mark[pos]){ //懒惰标记下移
        mark[pos << 1] += mark[pos];
        mark[(pos << 1)|1] += mark[pos];
        tree[pos << 1] += mark[pos] * (len - (len >> 1));
        tree[(pos << 1)|1] += mark[pos] * (len >> 1);
        mark[pos] = 0;
    }
    LL ret = 0;
    if(l <= m) ret += Query(l,r,L,m,pos << 1);
    if(r  > m) ret += Query(l,r,m + 1,R,(pos << 1)|1);
    return ret;
}
int main(){
    char str[MAXD];
    scanf("%d%d",&n,&m);
    BuildTree(1,n,1);
    for(int i = 0 ; i < m ; i++){
        scanf("%s",str);
        if(str[0] == 'Q'){
            int x ,y;
            scanf("%d%d",&x,&y);
            LL ans = Query(x,y,1,n,1);
            printf("%I64d\n",ans);
        }
        else if(str[0] == 'C'){
            int x,y,z;
            scanf("%d%d%d",&x,&y,&z);
            UpDate(x,y,z,1,n,1);
        }
    }
    return 0;
}

【POJ】A Simple Problem with Integers(线段树区间修增减求和)