XJOI网上同步训练DAY6 T2

思路:记得FJ省队集训好像有过这题，可是我太弱了，根本不懂T_T

 #include<cstdio>
 #include<iostream>
 #include<cmath>
 #include<cstring>
 #include<algorithm>
 int n,m;
 double f[][];
 int pd[][];
 int read(){
     int t=,f=;char ch=getchar();
     while (ch<''||ch>''){if (ch=='-')f=-;ch=getchar();}
     while (''<=ch&&ch<=''){t=t*+ch-'';ch=getchar();}
     return t*f;
 }
 void dfs(int n,int m){
     if (pd[n][m]) return;
     pd[n][m]=;
     if (n==||m==) f[n][m]=(1.0)/(m+);else{
         dfs(m-,n);dfs(m,n-);
         double x,y,x1,y1;
         x=m/(m+1.0)*(-f[m-][n])-,y=;
         x1=m/(m+1.0)*(-f[m-][n])+1.0/(m+)+(f[m][n-]-);
         y1=-f[m][n-];
         double a=(y1-y)/(x-x1);
         f[n][m]=a*x1+y1;
     }
 }
 int main(){
     n=read();m=read();
     dfs(n,m);
     printf("%.10f %.10f\n",f[n][m],-f[n][m]);
 }