n个最小和贪心思想，利用堆维护

Posted 2020-11-27 凌晨five点

  1 #include <iostream>
  2 #include <algorithm>
  3 #include <cstring>
  4 #include <queue>
  5 using namespace std;
  6 typedef long long LL;
  7 struct  node{
  8 	int a;
  9 	int b;
 10 	LL num;
 11 	bool operator < (const node other)const{
 12 		return num > other.num;
 13 	}
 14 };
 15 
 16 priority_queue<node> pq;
 17 
 18 LL A[1001][1001], t[1001];
 19 
 20 
 21 int main(){
 22 	int m, n;
 23 	node temp;
 24 	cin >> m >> n;
 25 	for(int i = 0; i < m; ++ i){
 26 		for(int j = 0; j < n; ++ j){
 27 			cin >> A[i][j];
 28 		}
 29 	}
 30 
 31 	for(int i = 0; i < m; ++ i){
 32 		sort(A[i], A[i] + n);
 33 	}
 34 	for(int i = 1; i < m; ++ i){
 35 		for(int j = 0; j < n; ++ j){
 36 			temp.a = j;
 37 			temp.b = 0;
 38 			temp.num = A[i-1][j] + A[i][0];
 39 			pq.push(temp);
 40 		}
 41 		for(int j = 0; j < n; ++ j){
 42 			temp = pq.top();
 43 			pq.pop();
 44 			t[j] = temp.num;
 45 			if(temp.b != n - 1){
 46 				temp.b++;
 47 				temp.num = A[i - 1][temp.a] + A[i][temp.b];
 48 				pq.push(temp);
 49 			}
 50 		}
 51 		for(int j = 0; j < n; ++ j){
 52 			A[i][j] = t[j];
 53 		}
 54 		//pq.clear();
 55 		while(!pq.empty()){
 56 			pq.pop();
 57 		}
 58 	}
 59 	cout << t[0];
 60 	for(int i = 1; i < n; ++ i){
 61 		cout << " " << t[i];
 62 	}
 63 	return 0;
 64 }