bzoj 1024 生日快乐 dfs

非常好理解的搜索，但要注意几个地方的浮点误差，能用整数尽量用整数……

#include<cstdio>#include<algorithm>#include<iostream>#include<cmath>using namespace std;double sqr;double dfs(double x,double y,int r){    if(r==1)        return x>y?x/y:y/x;    double ans=1e9;    double i=sqr/x;    int j=1;double q=i;    while(j<=r/2)    {        double dq=max(dfs(x,i,j),dfs(x,y-i,r-j));        ans=min(ans,dq);j++;i+=q;    }    i=sqr/y;    j=1;q=i;    while(j<=r/2)    {        double dq=max(dfs(i,y,j),dfs(x-i,y,r-j));        ans=min(ans,dq);j++;i+=q;    }    return ans;}int main(){    double x,y;int n;    cin>>x>>y>>n;    sqr=(x*y)/(double)n;    double i=sqr/x;    int j=1;    printf("%.6lf",dfs(x,y,n));    return 0; }