#include <bits/stdc++.h>
#pragma GCC optimize ("Ofast", "unroll-loops")
using namespace std;
#define ll long long
#define int ll
#define FOR(i,a,b) for (int i = (a); i<(b); i++)
#define REP(i,n) FOR(i,0,n)
#define REP1(i,n) FOR(i,1,n+1)
#define RREP(i,n) for (int i=(n)-1; i>=0; i--)
#define f first
#define s second
#define pb push_back
#define ALL(x) x.begin(),x.end()
#define SZ(x) (int)(x.size())
#define SQ(x) (x)*(x)
#define pii pair<int, int>
#define pdd pair<double ,double>
#define pcc pair<char, char>
#define endl '\n'
//#define TOAD
#ifdef TOAD
#define bug(x) cerr<<__LINE__<<": "<<#x<<" is "<<x<<endl
#define IOS()
#else
#define bug(...)
#define IOS() ios::sync_with_stdio(0), cin.tie(0), cout.tie(0)
#endif
const ll inf = 1ll<<60;
const int iinf=2147483647;
const ll mod = 1e9+7;
const ll maxn=1e5+5;
const double PI=acos(-1);
ll pw(ll x, ll p, ll m=mod){
ll ret=1;
while (p>0){
if (p&1){
ret*=x;
ret%=m;
}
x*=x;
x%=m;
p>>=1;
}
return ret;
}
ll inv(ll a, ll m=mod){
return pw(a,m-2);
}
//=======================================================================================
signed main (){
IOS();
int n; cin>>n;
string str; cin>>str;
int cntg=0, cntr=0;
REP(i,n){
if (str[i]=='R'){
cntr++;
}
else cntg++;
}
if (n%2){
if (cntg*2!=n-1&&cntr*2!=n-1){
cout<<-1<<endl;
return 0;
}
int cur=0;
int res=0;
if (cntr*2==n-1){
// G is in front
REP(i,n){
if (str[i]=='G'){
res+=abs(cur-i);
cur+=2;
}
}
}
else {
REP(i, n){
if (str[i]=='R'){
res+=abs(cur-i);
cur+=2;
}
}
}
cout<<res<<endl;
}
else {
if (cntg!=cntr){
cout<<-1<<endl;
return 0;
}
int cur=0, res=0;
REP(i, n){
if (str[i]=='G'){
res+=abs(i-cur);
cur+=2;
}
}
int ans=res;
cur=0; res=0;
REP(i, n){
if (str[i]=='G'){
res+=abs(i-cur);
cur+=2;
}
}
ans=min(ans, res);
cout<<ans<<endl;
}
}
/*
2 3
2 1
2 1
2
2
2
*/
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
384 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Incorrect |
1 ms |
212 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
384 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Incorrect |
1 ms |
212 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Incorrect |
1 ms |
320 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
384 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Incorrect |
1 ms |
212 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |