HackerEarth Bob and Bombs problem solution

#include<bits/stdc++.h>

using namespace std;

#define vi vector < int >
#define pii pair < int , int >
#define pb push_back
#define mp make_pair
#define ff first
#define ss second
#define foreach(it,v) for( __typeof((v).begin())it = (v).begin() ; it != (v).end() ; it++ )
#define ll long long
#define llu unsigned long long
#define MOD 1000000007
#define INF 0x3f3f3f3f
#define dbg(x) { cout<< #x << ": " << (x) << endl; }
#define dbg2(x,y) { cout<< #x << ": " << (x) << " , " << #y << ": " << (y) << endl; }
#define all(x) x.begin(),x.end()
#define mset(x,v) memset(x, v, sizeof(x))
#define sz(x) (int)x.size()

int main()
{
    int t;
    cin >> t;
    assert(1 <= t && t <= 10);
    while(t--)
    {
        string s;
        cin >> s;
        int n = sz(s) , i;
        int ans = 0 , pre = -1;
        assert(1 <= n && n <= 100000);
        for(i=0;i<n;i++)
        {
          assert(s[i] == 'B' || s[i] == 'W');
        }
        for(i=0;i<n;i++)
        {
            if(s[i] == 'B')
            {
              if(pre == -1)
              {
                ans += min(2,i);
              }
              else
              {
                ans += min(4,i - pre - 1);
              }
              pre = i;
            }
        }
        if(pre != -1)
          ans += min(2,n - pre - 1);
        printf("%dn",ans);
    }
    return 0;
}