CodeForces 405B 手速题

//CodeForces 405B

 1 #include "iostream"
 2 #include "cstdio"
 3 #include "cstring"
 4 #include "algorithm"
 5 using namespace std;
 6 char str[3010];
 7 int n;
 8
 9 int main()
10 {
11     int i, j, res = 0, pos;
12     char c;
13     scanf("%d%s", &n, str + 1);
14     str[n + 1] = ‘R‘;
15     for(i = 1; i <= n && str[i]==‘.‘; ++i);
16     if(str[i] == ‘R‘) {
17         res += (i - 1);
18         c = ‘R‘;
19         pos = i;
20     } else {
21         c = ‘L‘;
22         pos = i;
23     }
24     for(++i ; i <= n + 1; ++i) {
25         if(c == ‘R‘ && str[i] == ‘L‘) {
26             res += (i - pos - 1) & 1;
27         }
28         else if(c == ‘L‘ && str[i] == ‘R‘) {
29             res += (i - pos - 1);
30         }
31         if(str[i] != ‘.‘) {
32             c = str[i];
33             pos = i;
34         }
35     }
36     printf("%d\n", res);
37 }