#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
template<class T> using oset =
tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define ll long long
#define ld long double
#define ar array
#define vi vector<int>
#define vii vector<vector<int>>
#define pii pair<int, int>
#define pb push_back
#define all(x) x.begin(), x.end()
#define f first
#define s second
#define endl "\n"
const int MOD = 1e9+7;
const int inf = 1e9;
const ll linf = 1e18;
const int d4i[4]={-1, 0, 1, 0}, d4j[4]={0, 1, 0, -1};
const int d8i[8]={-1, -1, 0, 1, 1, 1, 0, -1}, d8j[8]={0, 1, 1, 1, 0, -1, -1, -1};
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
// -------------------------------------------------- Main Code --------------------------------------------------
/*
YRGGRRGGYY
dp[i][red][green][yellow][prevCol] = dp[i+1][]
RYRGY
*/
const int N = 405;
int n, arr[N], dp[N][N][N][4], countPrev[4][N];
vi pos[4];
int sol(int red, int green, int yellow, int prev) {
int idx = (red+green+yellow+1);
if (idx == n+1) return 0;
if (dp[red][green][yellow][prev] != -1) return dp[red][green][yellow][prev];
int ans = inf;
for (int j = 1; j <= 3; j++) {
if (j == prev) continue;
int cost = inf;
if (j == 1) {
red++;
if (red-1 < pos[j].size()) {
int p = pos[j][red-1];
cost = max(0, countPrev[2][p] - green) + max(0, countPrev[3][p] - yellow);
}
}
if (j == 2) {
green++;
if (green-1 < pos[j].size()) {
int p = pos[j][green-1];
cost = max(0, countPrev[1][p] - red) + max(0, countPrev[3][p] - yellow);
}
}
if (j == 3) {
yellow++;
if (yellow-1 < pos[j].size()) {
int p = pos[j][yellow-1];
cost = max(0, countPrev[2][p] - green) + max(0, countPrev[1][p] - red);
}
}
ans = min(ans, sol(red, green, yellow, j) + cost);
if (j == 1) red--; if (j == 2) green--; if (j == 3) yellow--;
}
return dp[red][green][yellow][prev] = ans;
}
void sol() {
memset(dp, -1, sizeof dp);
cin >> n;
string s; cin >> s;
for (int i = 0; i < n; i++) {
if (s[i] == 'R') arr[i+1] = 1;
if (s[i] == 'G') arr[i+1] = 2;
if (s[i] == 'Y') arr[i+1] = 3;
pos[arr[i+1]].pb(i+1);
countPrev[arr[i+1]][i+1] = 1;
}
for (int j = 1; j <= 3; j++) {
for (int i = 1; i <= n; i++) {
countPrev[j][i] += countPrev[j][i-1];
}
}
int ans = sol(0, 0, 0, 0);
cout << (ans==inf?-1:ans) << endl;
}
int main () {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int t = 1;
// cin >> t;
while (t--) {
sol();
}
return 0;
}
Compilation message
joi2019_ho_t3.cpp: In function 'int sol(int, int, int, int)':
joi2019_ho_t3.cpp:57:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
57 | if (red-1 < pos[j].size()) {
| ~~~~~~^~~~~~~~~~~~~~~
joi2019_ho_t3.cpp:64:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
64 | if (green-1 < pos[j].size()) {
| ~~~~~~~~^~~~~~~~~~~~~~~
joi2019_ho_t3.cpp:71:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
71 | if (yellow-1 < pos[j].size()) {
| ~~~~~~~~~^~~~~~~~~~~~~~~
joi2019_ho_t3.cpp:77:9: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
77 | if (j == 1) red--; if (j == 2) green--; if (j == 3) yellow--;
| ^~
joi2019_ho_t3.cpp:77:28: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
77 | if (j == 1) red--; if (j == 2) green--; if (j == 3) yellow--;
| ^~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Execution timed out |
554 ms |
1040212 KB |
Time limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Execution timed out |
554 ms |
1040212 KB |
Time limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
243 ms |
1040360 KB |
Output is correct |
2 |
Correct |
409 ms |
1040468 KB |
Output is correct |
3 |
Correct |
378 ms |
1040476 KB |
Output is correct |
4 |
Correct |
417 ms |
1040724 KB |
Output is correct |
5 |
Correct |
466 ms |
1040724 KB |
Output is correct |
6 |
Correct |
406 ms |
1040720 KB |
Output is correct |
7 |
Correct |
406 ms |
1040476 KB |
Output is correct |
8 |
Correct |
473 ms |
1040340 KB |
Output is correct |
9 |
Correct |
398 ms |
1040480 KB |
Output is correct |
10 |
Correct |
451 ms |
1040484 KB |
Output is correct |
11 |
Correct |
492 ms |
1040480 KB |
Output is correct |
12 |
Correct |
280 ms |
1040464 KB |
Output is correct |
13 |
Correct |
280 ms |
1040464 KB |
Output is correct |
14 |
Correct |
319 ms |
1040672 KB |
Output is correct |
15 |
Correct |
395 ms |
1040696 KB |
Output is correct |
16 |
Correct |
388 ms |
1040464 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Execution timed out |
554 ms |
1040212 KB |
Time limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |