题意：给出n个点的坐标，问取出其中任意点围成的区域的最小值！
很明显，找到一个合适的三角形即可。#include#include #include #include #include #include using namespace std; const int maxn = 100 + 10;const int INF = 0x3f3f3f3f;int T, N;struct Point{ double _x, _y;}p[maxn];double Cross(int A, int B, int C){ double ABx = p[B]._x - p[A]._x; double ABy = p[B]._y - p[A]._y; double ACx = p[C]._x - p[A]._x; double ACy = p[C]._y - p[A]._y; return fabs(ABx*ACy - ABy*ACx) / 2.0;}int main(){ // freopen("input.txt", "r", stdin); // freopen("output.txt", "w", stdout); scanf("%d", &T); while(T--) { scanf("%d", &N); for(int i = 0; i < N; i++) scanf("%lf %lf", &p[i]._x, &p[i]._y); double minn = INF; for(int i = 0; i < N; i++) for(int j = i + 1; j < N; j++) for(int k = j + 1; k < N; k++) { double s = Cross(i, j, k); if(s <= 1e-7) continue; minn = min(minn, s); } if(fabs(minn - INF) < 1e-6) printf("Impossible\n"); else printf("%.2lf\n", minn); }}