算法-ACM POJ

发布于 2017-01-08 02:26:40 字数 3764 浏览 1171 评论 1

Description
You have N integers, A1, A2, ... , 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 A1, A2, ... , AN. -1000000000 ≤ Ai ≤ 1000000000.
Each of the next Q lines represents an operation.
"C abc" means adding c to each of Aa, Aa+1, ... , Ab. -10000 ≤ c ≤ 10000.
"Q ab" means querying the sum of Aa, Aa+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

#include <stdio.h>
#include <algorithm>
#include <iostream>
using namespace std;

const int MAX = 100000;
int num[MAX];

struct Node
{
    int l, r;
    long long sum;
    long long inc;
}sTree[MAX*3];

void Build(int i, int l, int r)
{
    sTree[i].l = l;
    sTree[i].r = r;
    sTree[i].inc = 0;
    if( l == r )
    {
        sTree[i].sum = num[l];
        return;
    }
    int mid = (l+r)/2;
    Build(i<<1, l, mid);
    Build(i<<1|1, mid+1, r );
    sTree[i].sum = sTree[i<<1].sum+sTree[i<<1|1].sum; 
}

void Add(int i, int a, int b, long long c);
long long Query(int i, int a, int b);

int main()
{
    int n, q;
    char op;
    int a,b,c;
    while(scanf("%d%d", &n, &q) != EOF)
    {
        for( int i = 1; i <= n; ++i )
            scanf("%d", &num[i]);
        Build(1,1,n);
        
        while(q--)
        {
            cin>>op;
            if( op == 'C' )
            {
                scanf("%d%d%d",&a,&b,&c);
                Add(1,a,b,c);
            }
            else
            {
                scanf("%d%d",&a,&b);
                long long temp = Query(1,a,b);
                printf("%I64dn", temp );
            }
        }
    }
    return 0;
}

void Add(int i, int a, int b, long long c)
{
    if( a <= sTree[i].l && b >= sTree[i].r )
    {
        sTree[i].inc += c;
        sTree[i].sum += (sTree[i].r - sTree[i].l + 1)*c;
        return;
    }
    if( sTree[i].inc > 0 )
    {
        Add(i<<1, sTree[i<<1].l, sTree[i<<1].r, sTree[i].inc );
        Add(i<<1|1, sTree[i<<1|1].l, sTree[i<<1|1].r, sTree[i].inc);
        sTree[i].inc = 0;
    }
    if( a <= sTree[i<<1].r )
        Add(i<<1, a, b, c);
    if( b >= sTree[i<<1|1].l )
        Add(i<<1|1, a, b, c);
    sTree[i].sum = sTree[i<<1].sum + sTree[i<<1|1].sum;
}

long long Query(int i, int a, int b)
{
    if( sTree[i].l == a && sTree[i].r == b )
        return sTree[i].sum;

    int mid = (sTree[i].l+sTree[i].r)/2;
    if( sTree[i].inc > 0 )
    {
        Add(i<<1, sTree[i<<1].l, sTree[i<<1].r, sTree[i].inc );
        Add(i<<1|1, sTree[i<<1|1].l, sTree[i<<1|1].r, sTree[i].inc);
        sTree[i].inc = 0;
    }
    if ( b <= mid )
        return Query( i<<1, a, b);
    else if( a > mid )
        return Query( i<<1|1, a, b);
    else
        return Query( i<<1, a, mid)+Query(i<<1|1, mid+1, b);
}