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CodeForces-626A-Robot Sequence

2016-03-26 20:05 555 查看
Description

Calvin the robot lies in an infinite rectangular grid. Calvin's source code contains a list of
n commands, each either 'U', 'R', 'D', or 'L' — instructions to
move a single square up, right, down, or left, respectively. How many ways can Calvin execute a non-empty contiguous substrings of commands and return to the same square he starts in? Two substrings are considered different if they have different starting
or ending indices.

Input

The first line of the input contains a single positive integer,
n (1 ≤ n ≤ 200) — the number of commands.

The next line contains n characters, each either 'U', 'R', 'D', or 'L' —
Calvin's source code.

Output

Print a single integer — the number of contiguous substrings that Calvin can execute and return to his starting square.

Sample Input

Input
6
URLLDR


Output
2


Input
4
DLUU


Output
0


Input
7
RLRLRLR


Output
12


Hint

In the first case, the entire source code works, as well as the "RL" substring in the second and third characters.

Note that, in the third case, the substring "LR" appears three times, and is therefore counted three times to the total result.

给你一个数n,然后给你一个长度为n的字符串,字符串未L,R,U,D,代表四个方向中的一个,问这个字符串中,有多少个子串能够回到原点。

n才200,直接暴力就好了,我选择是统计子串的出现的次数,然后比较就好了

#include<cstdio>
#include<cstring>
#include<algorithm>
#include<iostream>
using namespace std;

char s[205];

int main()
{
int n;
while(scanf("%d",&n)!=EOF)
{
scanf("%s",s);
int num=0;
for(int i=0;i<n;i++)
{
int u=0,d=0,l=0,r=0;
for(int j=i;j<n;j++)
{
if(s[j]=='U')
u++;
if(s[j]=='D')
d++;
if(s[j]=='L')
l++;
if(s[j]=='R')
r++;
if(u==d&&r==l)
num++;
}
}
printf("%d\n",num);
}
return 0;
}
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