标签:des style http color java os io strong
3 3 1 2 3 3 1 2 4 4 1 9 100 10
1.000 2.000 8.000HintFor the first sample , a legal answer is [1,2] [2,3] so the length is 1. For the second sample , a legal answer is [-1,1] [2,4] so the answer is 2. For the thired sample , a legal answer is [-7,1] , [1,9] , [10,18] , [100,108] so the answer is 8.
我的原先想法是二分所有整数解
后来发现有可能是半整数
5
1 2 5 6 8
所以改成了验证所有小数,仍错
发现是因为没有考虑到1条segment同时覆盖2点的情况
仍WA,
发现答案一定是某段区间的长度(或一半)否则必定可以继续拉长线段
加入优化,过。可能原先的Tle显示成wa或者溢出?了
#include<cstdio> #include<cstring> #include<cstdlib> #include<algorithm> #include<functional> #include<iostream> #include<cmath> #include<cctype> #include<ctime> using namespace std; #define For(i,n) for(int i=1;i<=n;i++) #define Fork(i,k,n) for(int i=k;i<=n;i++) #define Rep(i,n) for(int i=0;i<n;i++) #define ForD(i,n) for(int i=n;i;i--) #define RepD(i,n) for(int i=n;i>=0;i--) #define Forp(x) for(int p=pre[x];p;p=next[p]) #define Lson (x<<1) #define Rson ((x<<1)+1) #define MEM(a) memset(a,0,sizeof(a)); #define MEMI(a) memset(a,127,sizeof(a)); #define MEMi(a) memset(a,128,sizeof(a)); #define INF (2139062143) #define F (100000007) #define MAXN (50+100) #define eps (1e-6) #define MAXLen (2000000000+10) long long mul(long long a,long long b){return (a*b)%F;} long long add(long long a,long long b){return (a+b)%F;} long long sub(long long a,long long b){return (a-b+(a-b)/F*F+F)%F;} typedef long long ll; int t,n,a[MAXN]; bool check(double x) { double t=a[1]; Fork(i,2,n-1) { if (t==(double)a[i]) continue; else if (t<=(double)a[i]-x) t=(double)a[i]; else if ((double)a[i]+x<=(double)a[i+1]) t=(double)a[i]+x; else return 0; } return 1; } int main() { cin>>t; while(t--) { cin>>n; For(i,n) scanf("%d",&a[i]); sort(a+1,a+1+n); double l=0,r=0,ans=0; Fork(i,2,n) { if (check((double)a[i]-a[i-1])) ans=max(ans,(double)a[i]-a[i-1]); else if (check(((double)a[i]-a[i-1])/2)) ans=max(ans,((double)a[i]-a[i-1])/2); } printf("%.3lf\n",ans); } return 0; }
BestCoder Round #4(Miaomiao's Geometry-贪心),布布扣,bubuko.com
BestCoder Round #4(Miaomiao's Geometry-贪心)
标签:des style http color java os io strong
原文地址:http://blog.csdn.net/nike0good/article/details/38688741