D - K Smallest Sums(多路归并+贪心)

Problem K

K Smallest Sums

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

---

Rujia Liu's Present 3: A Data Structure Contest Celebrating the 100th Anniversary of Tsinghua University
Special Thanks: Yiming Li
Note: Please make sure to test your program with the gift I/O files before submitting!

 #include <iostream>
 #include <cstdio>
 #include <cstring>
 #include <cmath>
 #include <algorithm>
 #include <string>
 #include <vector>
 #include <stack>
 #include <queue>
 #include <set>
 #include <map>
 #include <list>
 #include <iomanip>
 #include <cstdlib>
 #include <sstream>
 using namespace std;
 typedef long long LL;
 const int INF=0x5fffffff;
 const double EXP=1e-;
 const int MS=;
 int ans[MS],a[MS],n;
 struct node
 {
     int s,b;
     node(int s,int b):s(s),b(b){}
     bool operator <(const node &a)const
     {
         return s>a.s;
     }
 };

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

 int main()
 {
     while(scanf("%d",&n)!=EOF)
     {
         for(int i=;i<n;i++)
             scanf("%d",&ans[i]);
         sort(ans,ans+n);
         for(int i=;i<n;i++)
         {
             for(int j=;j<n;j++)
                 scanf("%d",&a[j]);
             sort(a,a+n);
             merge(ans,a,ans,n);
         }
         for(int i=;i<n;i++)
         {
             if(i)
                 printf(" ");
             printf("%d",ans[i]);
         }
         printf("\n");
     }
     return ;
 }