csp 2014_9_4 最优配餐

注意 变量的范围 要取long类型

题目链接

package csp2014_9_4;import java.util.Arrays;import java.util.LinkedList;import java.util.List;import java.util.Scanner;import org.w3c.dom.css.ViewCSS;public class Main {long[][]map;boolean [][]visit;int n, m, k, d;int [][]dir = {{0,1},{0,-1},{1,0},{-1,0}};long ans;LinkedList<Node> que;public static void main(String[] args) {new Main().run();}public void run() {Scanner in = new Scanner(System.in);while(in.hasNext()) {n = in.nextInt();m = in.nextInt();k = in.nextInt();d = in.nextInt();que = new LinkedList<>();visit = new boolean[n+1][n+1];map = new long[n+1][n+1];for(int i = 0; i < m; i++ ) {int x = in.nextInt();int y = in.nextInt();que.offer(new Node(x, y, 0));}for(int i = 0; i < k; i++ ) {int x = in.nextInt();int y = in.nextInt();long num = in.nextInt();map[x][y] = num; }for(int i = 0; i < d; i++ ) {int x = in.nextInt();int y = in.nextInt();visit[x][y] = true;}ans = 0;bfs();System.out.println(ans);}}public void bfs() {int cnt = 0;while(!que.isEmpty()) {Node node = que.poll();for(int i = 0; i < 4; i++ ) {int xx = node.x + dir[i][0];int yy = node.y + dir[i][1];if(xx>0&&yy>0&&xx<=n&&yy<=n&&!visit[xx][yy]) {visit[xx][yy] = true;ans += (node.step+1)*map[xx][yy];Node tmp = new Node(xx, yy, node.step+1);que.offer(tmp);}}}}}class Node{int x, y;long mum;long step;public Node(int x, int y, long s) {step = s;this.x = x;this.y = y;}}

上面 可以在达到目标后提前终止

if(map[xx][yy] != 0) {ans += (node.step+1)*map[xx][yy];cnt++;if(cnt == k)return;}