2018ICPC南京K. Kangaroo Puzzle

 1 #include<bits/stdc++.h>
 2 using namespace std;
 3 int main(void)
 4 {
 5     int n;
 6     srand(time(0));
 7     n = 50000;
 8     string s;
 9     char a[5]= "UDRL";
10     while(n--) s += a[rand()%4];
11     cout<<s<<endl; 
12    return 0;
13 }