#include <cstdio>
#include <stdio.h>
#include <stdbool.h>
#include <iostream>
#include <map>
#include <vector>
#include <climits>
#include <stack>
#include <string>
#include <queue>
#include <algorithm>
#include <set>
#include <unordered_set>
#include <unordered_map>
#include <cmath>
#include <cctype>
#include <bitset>
#include <iomanip>
#include <cstring>
#include <numeric>
#include <cassert>
#include <random>
#include <chrono>
#include <fstream>
using namespace std;
#define int long long
#define pii pair<int, int>
#define mp make_pair
#define pb push_back
#define fi first
#define se second
int32_t main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n;
string s;
cin>>n>>s;
s=' '+s;
vector<int> r, g, y;
vector<vector<int> > psum(3, vector<int>(n+1, 0));
for (int i=1; i<=n; ++i){
if (s[i]=='R')r.pb(i), ++psum[0][i];
else if (s[i]=='G')g.pb(i), ++psum[1][i];
else y.pb(i), ++psum[2][i];
psum[0][i]+=psum[0][i-1];
psum[1][i]+=psum[1][i-1];
psum[2][i]+=psum[2][i-1];
}
vector<vector<vector<vector<int> > > > dp(r.size()+1, vector<vector<vector<int> > >(g.size()+1, vector<vector<int> >(y.size()+1, vector<int>(3, LLONG_MAX/2))));
dp[0][0][0][0]=dp[0][0][0][1]=dp[0][0][0][2]=0;
for (int i=0; i<=r.size(); ++i)for (int j=0; j<=g.size(); ++j)for (int l=0; l<=y.size(); ++l)for (int p=0; p<3; ++p){
if (i&&p)dp[i][j][l][0]=min(dp[i][j][l][0], dp[i-1][j][l][p]+abs(j+l-psum[1][r[i-1]]-psum[2][r[i-1]]));
if (j&&p!=1)dp[i][j][l][1]=min(dp[i][j][l][1], dp[i][j-1][l][p]+abs(i+l-psum[0][g[j-1]]-psum[2][g[j-1]]));
if (l&&p!=2)dp[i][j][l][2]=min(dp[i][j][l][2], dp[i][j][l-1][p]+abs(j+i-psum[1][y[l-1]]-psum[0][y[l-1]]));
}
if (min({dp[r.size()][g.size()][y.size()][0], dp[r.size()][g.size()][y.size()][1], dp[r.size()][g.size()][y.size()][2]})==LLONG_MAX/2)cout<<-1;
else cout<<min({dp[r.size()][g.size()][y.size()][0], dp[r.size()][g.size()][y.size()][1], dp[r.size()][g.size()][y.size()][2]})/2;
}
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |