Insufficient comparator

[GauthamBanasandra]

UVa/volume117/11729 - Commando War.cpp

Lines 7 to 9 in 080fb3a

	bool cmp(pt a, pt b) {
	return a.y > b.y;
	}

The above code fails to provide consistent sorting order when y is the same for different x. For example -
3
3 10
2 10
1 10

Comparator must be -
if(a.y == b.y) { return a.x < b.x; } return a.y > b.y;