BZOJ1650: [Usaco2006 Dec]River Hopscotch 跳石子

来源：互联网发布：mac磁盘清理编辑：程序博客网时间：2024/06/05 18:33

题目链接：http://www.lydsy.com/JudgeOnline/problem.php?id=1650

水题，二分枚举答案，和NOIP2015d2t1一模一样……，bzoj上要权限这题#奥妙重重

贴代码

#include<cstdio>#include<cstring>#include<cstdlib>using namespace std;int L,R,len,ans,mid,n,m;int f[50005];bool check(int x){int sum=0,last=1;for (int i=2;i<=n;i++){if (f[i]-f[last]<x)sum++;else last=i;}return sum<=m;}void swap(int &x,int &y){int t;t=x;x=y;y=t;}void qsort(int L,int R){int i,j,mid;i=L;j=R;mid=f[rand()%(R-L+1)+L];do{while (f[i]<mid) i++;while (f[j]>mid) j--;if (i<=j) swap(f[i],f[j]),i++,j--;} while (i<=j);if (i<R) qsort(i,R);if (L<j) qsort(L,j);}int main(){//freopen("1650.in","r",stdin);//freopen("1650.out","w",stdout);scanf("%d%d%d",&len,&n,&m);int bo=0;for (int i=1;i<=n;i++) {scanf("%d",&f[i]);if (f[i]==0) bo=1;}if (bo==0) f[++n]=0;qsort(1,n);if (f[n]!=len)f[++n]=len; L=0;R=len;ans=0;while (L<=R){mid=(L+R)>>1;if (check(mid)) ans=mid,L=mid+1;else R=mid-1;}printf("%d",ans);return 0;}

【写的有漏洞的，欢迎路过大神吐槽】

2017/1/4 22:11:48

Ending.

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