hihoCoder 1227 The Cats' Feeding Spots(水)

hihoCoder 1227 The Cats' Feeding Spots(水)"/>

hihoCoder 1227 The Cats' Feeding Spots(水)

题目链接：hihoCoder 1227 The Cats’ Feeding Spots

代码

#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>using namespace std;
const int maxn = 105;
const int inf = 0x3f3f3f3f;int M, N;
double X[maxn], Y[maxn], D[maxn][maxn];double dis(double x, double y) {return sqrt(x*x + y*y);
}int main () {int cas;scanf("%d", &cas);for (int kcas = 1; kcas <= cas; kcas++) {scanf("%d%d", &M, &N);for (int i = 1; i <= M; i++) {scanf("%lf%lf", &X[i], &Y[i]);for (int j = 1; j <= i; j++)D[i][j] = D[j][i] = dis(X[i]-X[j], Y[i]-Y[j]);}int ans = inf;for (int i = 1; i <= M; i++) {sort(D[i] + 1, D[i] + 1 + M);int r = ceil(D[i][N]);for (int k = 0; k < 2; k++) {int c = 0, flag = 1;for (int j = 1; j <= M && flag; j++) {if (fabs(D[i][j] - r) < 1e-6) flag = 0;if (D[i][j] < r) c++;}if (flag && c == N) {ans = min(ans, r);}r++;}}if (ans == inf) ans = -1;printf("%d\n", ans);}return 0;
}