bai 9

#include<stdio.h>
void toigian(int &x, int &y)
{
	for (int i = x; i > 0; i--) {
		if (x%i == 0 && y%i == 0) { x = x / i; y = y / i; }
	}
}
void main()
{
	int a[20];
	int b[20];
	int g = 0;
	for (int i = 2; i <= 7; i++) {
		for (int j = 1; j < i; j++) {
			int x = j;
			int y = i;
			toigian(x, y);
			if (y != i)continue;
			a[g] = x;
			b[g] = y;
			g++;
		}
	}
	int n = g-1;
	int m = g;
	for (int j = 0; j < m; j++) {
		for (int i = 0; i < g; i++) {                   //tim gia tri lon nhat de hoan gia tri voi a[n],b[n] sau do giam n 1 don vi
			int x, y;
			if (a[i] * b[n]>a[n] * b[i]) {
				x = a[i];
				y = b[i];
				a[i] = a[n];
				b[i] = b[n];
				a[n] = x;
				b[n] = y;
			}
		}
		n--;
		g--;
	}
	for (int i = 0; i < m; i++) {
		printf("%i / %i\t", a[i], b[i]);
	}
}