#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vll = vector <ll>;
using vi = vector <int>;
vi ou[3];
int dp[403][403][403][3]; // dp[a][b][c][last] = min operations to have a valid string\
rn having a prefix of length a+b+c having taken a as, b bs, and c cs, having the last color as last
int dp2[403][403][403][3]; // dp2[a][b][c][wh] =
int fcost (int a, int b, int c, int wh) { // calculates the followisg sum:
/*
for (ll j = 0; j < a; j++) if (ou[0][j] < ou[wh][t]) ans++;
for (ll j = 0; j < b; j++) if (ou[1][j] < ou[wh][t]) ans++;
for (ll j = 0; j < c; j++) if (ou[2][j] < ou[wh][t]) ans++;
*/
if (dp2[a][b][c][wh] <= 1e9) return dp2[a][b][c][wh];
int t = wh == 0 ? a : wh == 1 ? b : c;
if ((a ? ou[0][a-1] : -1) >= ou[wh][t]) return dp2[a][b][c][wh] = fcost(a-1, b, c, wh);
if ((b ? ou[1][b-1] : -1) >= ou[wh][t]) return dp2[a][b][c][wh] = fcost(a, b-1, c, wh);
if ((c ? ou[2][c-1] : -1) >= ou[wh][t]) return dp2[a][b][c][wh] = fcost(a, b, c-1, wh);
return dp2[a][b][c][wh] = a+b+c;
}
ll n;
int bey[3]; // bey[i] = how many taken are beyond the last taken of color i
int ptr[3][3];
// bool taken[403];
int solve (ll a, ll b, ll c, ll last) { // have taken the first a as b bs and c cs, the last rn is last
if (a+b+c == n) return 0;
if (dp[a][b][c][last] <= 1e9) return dp[a][b][c][last];
int &ans = dp[a][b][c][last];
ans = 1e9;
int i = a+b+c;
// ll lsa = a < ou[0].size() ? ou[0][a] : n;
// ll lsb = b < ou[1].size() ? ou[1][b] : n;
// ll lsc = c < ou[2].size() ? ou[2][c] : n;
// auto costFor = [&](ll col, ll t) {
// int ans = 0;
// ptr[col][0] = 0;
// // while (ptr[col][0] >= 0 && ou[0][ptr[col][0]] > ou[col][t]) ptr[col][0]--;
// while (ptr[col][0] < ou[0].size() && ou[0][ptr[col][0]] < ou[col][t]) ptr[col][0]++;
// ans += min((int)a, ptr[col][0]);
// // for (ll j = 0; j < a; j++) if (ou[0][j] < ou[col][t]) ans++;
// for (ll j = 0; j < a; j++) if (ou[0][j] < ou[col][t]) ans++;
// for (ll j = 0; j < b; j++) if (ou[1][j] < ou[col][t]) ans++;
// for (ll j = 0; j < c; j++) if (ou[2][j] < ou[col][t]) ans++;
// return ans;
// };
if (last != 0 && a < ou[0].size()) { ans = min(ans, solve(a+1, b, c, 0) + ou[0][a] - fcost(a, b, c, 0)); }
if (last != 1 && b < ou[1].size()) { ans = min(ans, solve(a, b+1, c, 1) + ou[1][b] - fcost(a, b, c, 1)); }
if (last != 2 && c < ou[2].size()) { ans = min(ans, solve(a, b, c+1, 2) + ou[2][c] - fcost(a, b, c, 2)); }
return ans;
}
int main () {
cin.tie(nullptr) -> sync_with_stdio(false);
cin >> n;
string str;
cin >> str;
memset(dp, 0x3f, sizeof(dp));
memset(dp2, 0x3f, sizeof(dp2));
// ou[0] = ou[1] = ou[2] = { -1 };
for (ll i = 0; i < n; i++) {
ou[(str[i] == 'R' ? 0 : str[i] == 'G' ? 1 : 2)].push_back(i);
}
ll ans = min({ solve(0, 0, 0, 0), solve(0, 0, 0, 1), solve(0, 0, 0, 2) });
cout << (ans == 1e9 ? -1 : ans) << '\n';
return 0;
}
Compilation message
joi2019_ho_t3.cpp:8:27: warning: multi-line comment [-Wcomment]
8 | int dp[403][403][403][3]; // dp[a][b][c][last] = min operations to have a valid string\
| ^
joi2019_ho_t3.cpp: In function 'int solve(ll, ll, ll, ll)':
joi2019_ho_t3.cpp:51:24: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
51 | if (last != 0 && a < ou[0].size()) { ans = min(ans, solve(a+1, b, c, 0) + ou[0][a] - fcost(a, b, c, 0)); }
| ~~^~~~~~~~~~~~~~
joi2019_ho_t3.cpp:52:24: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
52 | if (last != 1 && b < ou[1].size()) { ans = min(ans, solve(a, b+1, c, 1) + ou[1][b] - fcost(a, b, c, 1)); }
| ~~^~~~~~~~~~~~~~
joi2019_ho_t3.cpp:53:24: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
53 | if (last != 2 && c < ou[2].size()) { ans = min(ans, solve(a, b, c+1, 2) + ou[2][c] - fcost(a, b, c, 2)); }
| ~~^~~~~~~~~~~~~~
joi2019_ho_t3.cpp:35:9: warning: unused variable 'i' [-Wunused-variable]
35 | int i = a+b+c;
| ^
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
446 ms |
1048576 KB |
Execution killed with signal 9 |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
446 ms |
1048576 KB |
Execution killed with signal 9 |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Execution timed out |
540 ms |
1048576 KB |
Time limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
446 ms |
1048576 KB |
Execution killed with signal 9 |
| 2 |
Halted |
0 ms |
0 KB |
- |
