#include <stdio.h>
#define LEN 3
int main()
{
int matrix[][LEN] = { { 1, 2, 3 },
{ 5, 6, 7 },
{ 8, 7, 9 } };
int rows = sizeof(matrix) / sizeof(matrix[0]);
int cols = sizeof(matrix[0]) / sizeof(matrix[0][0]);
// left
for (int i = 0; i < rows; i++) {
printf("%3d", matrix[i][i]);
}
printf("\n");
// right
for (int i = 0, j = cols - 1; i < rows; i++, j--) {
printf("%3d", matrix[i][j]);
}
printf("\n");
return 0;
}
/*
run:
1 6 9
3 6 8
*/