Java实现 洛谷 P1208 [USACO1.3]混合牛奶 Mixing Milk

输入输出样例
输入 #1

100 5
5 20
9 40
3 10
8 80
6 30

输出 #1

630

import java.util.Arrays;
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		while (sc.hasNext()) {
			int m = sc.nextInt();
			int n = sc.nextInt();
			int x[] = new int[n];           //用于存储排序后的数据
			int y[][] = new int[n][2];     //存储原数据
			int z[] = new int[n];         //识别是否买过；
			long sum = 0;
			for (int i = 0; i < n; i++) {
				y[i][1] = sc.nextInt();
				y[i][0] = sc.nextInt();
				x[i] = y[i][1];
			}
			Arrays.sort(x);
			TO：
			for (int i = 0; i < n; i++) {
				for (int j = 0; j < n; j++) {     //双层循环用于找到该单价情况下的奶牛数
					if (x[i] == y[j][1] && z[j] == 0) {
						if (m >= y[j][0]) {
							z[j] = 1;
							sum += y[j][1] * y[j][0];
							m -= y[j][0];
							break;     //结束本次内循环
						} else {
							z[j] = 1;
							sum += y[j][1] * m;
							m = 0;
							break TO;   //结束整个双层循环
						}
					}
				}
			}
			System.out.println(sum);
		}
	}
}