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poj 3468 A Simple Problem with Integers(线段树)

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A Simple Problem with Integers
Time Limit: 5000MS   Memory Limit: 131072K
Total Submissions: 61636   Accepted: 18840
Case Time Limit: 2000MS

Description

You have N integers, A1A2, ... , AN. You need to deal with two kinds of operations. One type of operation is to add some given number to each number in a given interval. The other is to ask for the sum of numbers in a given interval.

Input

The first line contains two numbers N and Q. 1 ≤ N,Q ≤ 100000.
The second line contains N numbers, the initial values of A1A2, ... , AN. -1000000000 ≤ Ai ≤ 1000000000.
Each of the next Q lines represents an operation.
"C a b c" means adding c to each of AaAa+1, ... , Ab. -10000 ≤ c ≤ 10000.
"Q a b" means querying the sum of AaAa+1, ... , Ab.

Output

You need to answer all Q commands in order. One answer in a line.

Sample Input

10 5
1 2 3 4 5 6 7 8 9 10
Q 4 4
Q 1 10
Q 2 4
C 3 6 3
Q 2 4

Sample Output

4
55
9
15

Hint

The sums may exceed the range of 32-bit integers.


题解及代码:


#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <set>
#include <map>
#include <queue>
#include <string>
#define maxn 100010
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
#define ALL %I64d
using namespace std;
typedef __int64  ll;

struct segment
{
    int l,r;
    ll value;
    ll nv;
} son[maxn<<2];

void PushUp(int rt)
{
    son[rt].value=son[rt<<1].value+son[rt<<1|1].value;
}

void Build(int l,int r,int rt)
{
    son[rt].l=l;
    son[rt].r=r;
    son[rt].nv=0;
    if(l==r)
    {
        scanf("%I64d",&son[rt].value);
        return;
    }
    int m=(l+r)/2;
    Build(lson);
    Build(rson);
    PushUp(rt);
}


void Update_n(ll w,int l,int r,int rt)
{
    if(son[rt].l==l&&son[rt].r==r)
    {
        son[rt].value+=w*(r-l+1);
        son[rt].nv+=w;
        return;
    }

    if(son[rt].nv)
    {
        son[rt<<1].nv+=son[rt].nv;
        son[rt<<1|1].nv+=son[rt].nv;
        son[rt<<1].value+=(son[rt<<1].r-son[rt<<1].l+1)*son[rt].nv;
        son[rt<<1|1].value+=(son[rt<<1|1].r-son[rt<<1|1].l+1)*son[rt].nv;
        son[rt].nv=0;
    }

    int m=(son[rt].l+son[rt].r)/2;

    if(r<=m)
        Update_n(w,l,r,rt<<1);
    else if(l>m)
        Update_n(w,l,r,rt<<1|1);
    else
    {
        Update_n(w,lson);
        Update_n(w,rson);
    }
    PushUp(rt);
}


ll  Query(int l,int r,int rt)
{
    if(son[rt].l==l&&son[rt].r==r)
    {
        return son[rt].value;
    }

    if(son[rt].nv)
    {
        son[rt<<1].nv+=son[rt].nv;
        son[rt<<1|1].nv+=son[rt].nv;
        son[rt<<1].value+=(son[rt<<1].r-son[rt<<1].l+1)*son[rt].nv;
        son[rt<<1|1].value+=(son[rt<<1|1].r-son[rt<<1|1].l+1)*son[rt].nv;
        son[rt].nv=0;
    }

    ll ret=0;
    int m=(son[rt].l+son[rt].r)/2;

    if(r<=m)
        ret=Query(l,r,rt<<1);
    else if(l>m)
        ret=Query(l,r,rt<<1|1);
    else
    {
        ret=Query(lson);
        ret+=Query(rson);
    }
    //PushUp(rt);
    return ret;
}
int main()
{
    int n,m,l,r;
    ll w;
    char s[4];
    while(scanf("%d%d",&n,&m)!=EOF)
    {
        Build(1,n,1);
        for(int i=1; i<=m; i++)
        {
            scanf("%s",s);
            if(s[0]=='C')
            {
                scanf("%d%d%I64d",&l,&r,&w);
                Update_n(w,l,r,1);
            }
            else
            {
                scanf("%d%d",&l,&r);
                printf("%I64d\n",Query(l,r,1));
            }
        }
    }
    return 0;
}

/*
作为初学者,写起程序也总是会出现一些小毛病,都是对于线段树的理解不深造成的。

说一下这道题目需要注意的地方,那就是无论是每个节点的值还是增量,都要使用long long,
否则会错掉。

经过这段时间的学习,弄懂了线段树的好多地方,现在感觉做题也没那么费力了,都是简单题目,
对于初学者来说还是比较好的,欢迎大家一起讨论学习。
*/



poj 3468 A Simple Problem with Integers(线段树),布布扣,bubuko.com

poj 3468 A Simple Problem with Integers(线段树)

标签:des   style   color   使用   os   io   strong   for   

原文地址:http://blog.csdn.net/knight_kaka/article/details/38581923

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