C :

#include <stdio.h>

int isObtuseTriangle(int, int, int, int, int, int);

int main()
{
	int T, N, points[128][2], i, j, k, count;
	
	scanf("%d", &T);
	while (T--){
		
		scanf("%d", &N);
		if (N < 3){
			printf("%d\n", 0);
			continue;
		}
		for (i = 0; i < N; i++){
			scanf("%d%d", &points[i][0], &points[i][1]);
		}
		
		count = 0;
		for(i = 0; i < N; i++){
			for(j = i + 1; j < N; j++){
				for(k = j + 1; k < N; k++){
					count += isObtuseTriangle(points[i][0],points[i][1],
                                              points[j][0],points[j][1],
											  points[k][0],points[k][1]);
				}
			}
		}
		printf("%d\n", count);
	}
	
	return 0;
}

int isObtuseTriangle(int x1, int y1, int x2, int y2, int x3, int y3)
{
	int sideSquare[3], tmp, slope[2];
	
	if (x1 == x2 && x1 == x3){
		return 0;
	}
	slope[0] = (y2-y1)*(x3-x2);
	slope[1] = (y3-y2)*(x2-x1);
	if (slope[0] == slope[1]){
		return 0;
	}
	
	sideSquare[0] = (x1-x2)*(x1-x2)+(y1-y2)*(y1-y2);
	sideSquare[1] = (x1-x3)*(x1-x3)+(y1-y3)*(y1-y3);
	sideSquare[2] = (x3-x2)*(x3-x2)+(y3-y2)*(y3-y2);
	
	if (sideSquare[1] > sideSquare[0]){
		tmp = sideSquare[1];
		sideSquare[1] = sideSquare[0];
		sideSquare[0] = tmp;
	}
	if (sideSquare[2] > sideSquare[0]){
		tmp = sideSquare[2];
		sideSquare[2] = sideSquare[0];
		sideSquare[0] = tmp;
	}
	
	if (sideSquare[0] > (sideSquare[1] + sideSquare[2])){
		return 1;
	}
	
	return 0;
}