算法训练 关联矩阵 问题描述

//有一个n个结点m条边的有向图，请输出他的关联矩阵。 输入格式 　　第一行两个整数n、m，
//表示图中结点和边的数目。n<=100,m<=1000。 　　接下来m行，每行
import java.util.Scanner;
public class Main{
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner in = new Scanner(System.in);
int n, m;
n = in.nextInt();
m = in.nextInt();
int[][] a = new int[m][2];
int[][] b = new int
[m];
for (int i = 0; i < m; i++) {
for (int j = 0; j < 2; j++) {
a[i][j] = in.nextInt();
}
}

for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
b[i][j] = 0;
}
}

for (int i = 0; i < m; i++) {
b[a[i][0]-1][i] = 1;
b[a[i][1]-1][i] = -1;
}

for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
System.out.print(b[i][j]+" ");
}
System.out.println();
}
}
}