题目中公式j的范围写错了,误导人。应该是0<= j < z;
import java.util.*;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
while(sc.hasNextInt()) {
int x = sc.nextInt();
int y = sc.nextInt();
int z = sc.nextInt();
int[][] a = new int[x][y];
for (int i =0; i < x; i++) {
for (int j =0; j< y; j++) {
a[i][j] = sc.nextInt();
}
}
int[][] b = new int[y][z];
for (int i =0; i < y; i++) {
for (int j =0; j< z; j++) {
b[i][j] = sc.nextInt();
}
}
int[][] c = new int[x][z];
for (int i =0; i < x; i++) {
for (int j =0; j< z; j++) {
for (int k =0; k < y; k++) {
c[i][j] += a[i][k] * b[k][j];
}
}
}
for (int i =0; i < x; i++) {
for (int j =0; j< z; j++) {
System.out.print(c[i][j]);
if (j != z-1) {
System.out.print(" ");
}
}
System.out.println("");
}
}
}
}