poj 3468 A Simple Problem with Integers

A Simple Problem with Integers

Time Limit: 5000MS		Memory Limit: 131072K
Total Submissions: 70937		Accepted: 21874
Case Time Limit: 2000MS

Description

You have N integers, A₁, A₂, ... , A_N. 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 A₁, A₂, ... , A_N. -1000000000 ≤ A_i ≤ 1000000000.
Each of the next Q lines represents an operation.
"C a b c" means adding c to each of A_a, A_a+1, ... , A_b. -10000 ≤ c ≤ 10000.
"Q a b" means querying the sum of A_a, A_a+1, ... , A_b.

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.

题目链接：http://poj.org/problem?id=3468

线段树成段更新，成段求和。

要注意的就是可能会超过int，要用long long 

#include <iostream>
#include <cstring>
#include <cstdio>
#include <string>
#include <iomanip>
using namespace std;
#define maxn 100010
#define lson l, m, rt<<1
#define rson m+1, r, rt<<1|1
long long sum[maxn<<2], col[maxn<<2];
int N, Q;
void PushUP(int rt){
    sum[rt] = sum[rt<<1] + sum[rt<<1|1];
}
void PushDown(int rt, int len){
    if(col[rt]){
        col[rt<<1] += col[rt];
        col[rt<<1|1] += col[rt];
        sum[rt<<1] += col[rt]*(len-(len>>1));
        sum[rt<<1|1] += col[rt]*(len>>1);
        col[rt] = 0;
    }
}
void build(int l, int r, int rt){
    col[rt] = 0;
    if(l == r){
        scanf("%lld", &sum[rt]);
        return;
    }
    int m = (r+l)>>1;
    build(lson);
    build(rson);
    PushUP(rt);
}
void update(int L, int R, int c, int l, int r, int rt){
    if(L <= l && r <= R){
        col[rt] += c;
        sum[rt] += c*(r-l+1);
        return;
    }
    PushDown(rt, r-l+1);
    int m = (l+r)>>1;
    if(L <= m) update(L, R, c, lson);
    if(R > m) update(L, R, c, rson);
    PushUP(rt); 
}
long long  query(int L, int R, int l, int r, int rt){
    if(L <= l && r <= R){
        return sum[rt];
    }
    PushDown(rt, r-l+1);
    int m = (l+r)>>1;
    long long  ret = 0;
    if(L <= m) ret += query(L, R, lson);
    if(m < R) ret += query(L, R, rson);
    return ret; 
}
int main(){
    while(~scanf("%d%d", &N, &Q)){
        build(1, N, 1);
        while(Q--){
            char ch; cin>>ch;
            int a, b, c;
            if(ch == 'Q'){
                scanf("%d%d", &a, &b);
                printf("%lld
",query(a,b,1,N,1));
            }
            else if(ch == 'C'){
                scanf("%d%d%d", &a, &b, &c);
                update(a, b, c, 1, N, 1);
            }
        }
    }
    
    return 0;
}