POJ-3111

来源：互联网发布：31周b超数据判断男女编辑：程序博客网时间：2024/06/06 15:47

还是二分查找，这几题都差不多，很快就水完了。。这题开始因为精度设的太小WA了一次，设到1e-6就可以A了

#include<cstdio>#include<algorithm>using namespace std;namespace{struct Jew{int v, w, index;double value;} dat[100000];int n, k;const double eps = 1e-6;bool cmp(struct Jew j1, struct Jew j2){return j1.value > j2.value;}bool check(double s){for (int i = 0; i < n; i++)dat[i].value = dat[i].v - s * dat[i].w;sort(dat, dat + n, cmp);double sum = 0;for (int i = 0; i < k; i++)sum += dat[i].value;return sum >= 0;}void solve(double ub){double lb = 0, mid;while (lb + eps < ub){mid = (lb + ub) / 2;if (check(mid))lb = mid;elseub = mid;}for (int i = 0; i < k; i++)printf(i ? " %d" : "%d", dat[i].index);puts("");}}int main(){scanf("%d %d", &n, &k);double maxx = 0;for (int i = 0; i < n; i++){scanf("%d %d", &dat[i].v, &dat[i].w);dat[i].index = i + 1;maxx = max(maxx, dat[i].v * 1.0 / dat[i].w);}solve(maxx);return 0;}

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