学步园

//多路归并问题
//把k个有序表合并成一个有序表。
//大于2是两两归并
//本题只要求出k个最小的，所以可以限制上限
//k个整数数组，每个数组包含k个数，在每个数组中
//去一个数加起来，得到K^K个和
//求这些和中的最小的k个值

You're given k arrays, each array has k integers. There are k^k ways to pick exactly one element in each array and calculate the sum of the integers. Your task is to find the k smallest sums among them.

Input

There will be several test cases. The first line of each case contains an integer k (2<=k<=750). Each of the following k lines contains k positive integers in each array. Each of these integers does not exceed 1,000,000. The input is terminated by end-of-file
(EOF). The size of input file does not exceed 5MB.

Output

For each test case, print the k smallest sums, in ascending order.

Sample Input

3
1 8 5
9 2 5
10 7 6
2
1 1
1 2

Output for the Sample Input

9 10 12
2 2

#include<iostream>
#include<cstdio>
#include<cstring>
#include<string>
#include<algorithm>
#include<queue>

using namespace std;

int  a[800][800],k;

struct node
{
    int s,b;
    bool operator<(const node &a) const
    {
        return s>a.s;
    }
};

void merge(int *A,int *B,int *C,int n)
{
    node tmp;
    priority_queue<node> q;
    for(int i=0;i<n;i++)
    {
        tmp.s=A[i]+B[0],tmp.b=0;
        q.push(tmp);
    }
    for(int i=0;i<n;i++)
    {
        tmp=q.top();
        q.pop();
        C[i]=tmp.s;
        if(tmp.b+1<n)
        {
            tmp.s=tmp.s-B[tmp.b]+B[tmp.b+1];
            tmp.b++;
            q.push(tmp);
        }
    }
}

int main()
{
    while(~scanf("%d",&k))
    {
        for(int i=0;i<k;i++)
        {
            for(int j=0;j<k;j++)
                scanf("%d",&a[i][j]);
            sort(a[i],a[i]+k);
        }
        for(int i=1;i<k;i++)
            merge(a[0],a[i],a[0],k);
        for(int i=0;i<k;i++)
            printf("%d%s",a[0][i],i!=k-1?" ":"\n");
    }
    return 0;
}