#include <iostream>
#include <iomanip>
#include <cstdio>
#include <vector>
#include <bitset>
#include <string>
#include <cstring>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <deque>
#include <utility>
#include <algorithm>
#include <random>
#include <cmath>
#include <cassert>
#include <climits>
#include <ctime>
#include <chrono>
#pragma GCC optimize("Ofast")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,sse4.1,sse4.2,popcnt,abm,mmx,avx,avx2,tune=native")
#ifdef LOCAL
#define dbg(x) cout << #x << " : " << x << endl;
#else
#define dbg(x)
#endif
#define pb push_back
#define ppb pop_back()
#define mp make_pair
#define fi(a, b) for (int i = a; i < b; i++)
#define fj(a, b) for (int j = a; j < b; j++)
#define fk(a, b) for (int k = a; k < b; k++)
#define fi1(a, b) for (int i = a - 1; i >= b; i--)
#define fj1(a, b) for (int j = a - 1; j >= b; j--)
#define fk1(a, b) for (int k = a - 1; k >= b; k--)
#define fx(x, a) for (auto& x : a)
#define rep(i, a, b) for (int i = a; i < b; ++i)
#define rep1(i, a, b) for (int i = a - 1; i >= b; --i)
#define siz(x) (int)x.size()
#define lb lower_bound
#define ub upper_bound
#define all(x) x.begin(), x.end()
using namespace std;
template<typename T1, typename T2>inline void mine(T1 &x, const T2 &y) { if (y < x) x = y; }
template<typename T1, typename T2>inline void maxe(T1 &x, const T2 &y) { if (x < y) x = y; }
ostream& operator << (ostream &out, const vector<int> &b) {
for (auto k : b) out << k << ' ';
return out;
}
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef char ch;
typedef string str;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<pii> vpii;
typedef vector<vpii> vvpii;
typedef vector<ch> vch;
typedef vector<vch> vvch;
typedef vector<str> vs;
const int MOD = 1000000007;
const int INF = 1000000050;
const long long BIG = (long long)2e18 + 50;
#ifdef LOCAL
const int MX = 20;
#else
const int MX = 410;
#endif
const double EPS = 1e-9;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int n;
int cnt[MX][3];
int dp[MX][MX / 2][MX / 2][3]; // pref cur0 cur1 last
int p[3];
int np[3];
int32_t main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin >> n;
vi a(n);
fx(x, a) {
char c;
cin >> c;
if (c == 'R')
x = 0;
else if (c == 'G')
x = 1;
else
x = 2;
}
fi(1, n + 1) {
fj(0, 3) {
cnt[i][j] = cnt[i - 1][j];
}
cnt[i][a[i - 1]]++;
}
fj(0, 3) {
if (cnt[n][j] > (n + 1) / 2) {
cout << "-1\n";
return 0;
}
}
int c0 = cnt[n][0];
int c1 = cnt[n][1];
int c2 = cnt[n][2];
fi(0, MX) fj(0, MX / 2) fk(0, MX / 2) for (int l = 0; l < 3; ++l) dp[i][j][k][l] = INF;
if (c2) dp[1][0][0][2] = 1 - cnt[1][2];
if (c1) dp[1][0][1][1] = 1 - cnt[1][1];
if (c0) dp[1][1][0][0] = 1 - cnt[1][0]
fi(1, n) {
int b0 = min(c0, i);
int b1 = min(c1, i);
for (p[0] = 0; p[0] <= b0; ++p[0]) {
for (p[1] = 0; p[1] <= b1; ++p[1]) {
p[2] = i - p[0] - p[1];
if (p[2] < 0) break;
if (p[2] > c2) continue;
memcpy(np, p, sizeof(p));
for (int l = 0; l < 3; ++l) {
if (i && !p[l]) continue;
for (int l2 = 0; l2 < 3; ++l2) {
if (l2 == l) continue;
np[l2]++;
int delta = 0;
for (int col = 0; col < 3; ++col)
delta += abs(np[col] - cnt[i + 1][col]);
mine(dp[i + 1][np[0]][np[1]][l2], dp[i][p[0]][p[1]][l] + delta);
np[l2]--;
}
}
}
}
}
int ans = INF;
for (int l = 0; l < 3; ++l) {
mine(ans, dp[n][c0][c1][l]);
}
assert(ans != INF && ans % 2 == 0);
cout << ans / 2 << '\n';
}
Compilation message
joi2019_ho_t3.cpp: In function 'int32_t main()':
joi2019_ho_t3.cpp:138:40: error: expected ';' before 'for'
138 | if (c0) dp[1][1][0][0] = 1 - cnt[1][0]
| ^
| ;
joi2019_ho_t3.cpp:41:34: error: 'i' was not declared in this scope
41 | #define fi(a, b) for (int i = a; i < b; i++)
| ^
joi2019_ho_t3.cpp:140:5: note: in expansion of macro 'fi'
140 | fi(1, n) {
| ^~
