#include <bits/stdc++.h>
using namespace std;
#ifdef DEBUG
#define DBGRUN(stmt) stmt
#define DBG1(x) cout << #x << ": " << (x) << endl
#define DBG2(x, y) cout << #x << ": " << (x) << ", " << #y << ": " << (y) << endl
#define DBG3(x, y, z) cout << #x << ": " << (x) << ", " << #y << ": " << (y) << ", " << #z << ": " << (z) << endl
#define DBG4(w, x, y, z) cout << #w << ": " << (w) << ", " << #x << ": " << (x) << ", " << #y << ": " << (y) << ", " << #z << ": " << (z) << endl
#define DBG_ARR(a, e) cout << #a << ": "; for (int i = 0; i < e; i++) cout << a[i] << ' '; cout << endl
#define DBG_ARR2D(a, s1, e1, s2, e2) cout << #a << ": " << endl; for (int i = s1; i < e1; i++) { for (int j = s2; j < e2; j++) cout << a[i][j] << ' '; cout << '\n'; }cout << endl
#define DBG_VEC(v) cout << #v << ": "; for (auto i : v) cout << i << ' '; cout << endl
#define DBG_HERE cout << "reached line: " << __LINE__ << endl
#else
#define DBGRUN(stmt)
#define DBG1(x)
#define DBG2(x, y)
#define DBG3(x, y, z)
#define DBG4(w, x, y, z)
#define DBG_ARR(a, e)
#define DBG_ARR2D(a, s1, e1, s2, e2)
#define DBG_VEC(v)
#define DBG_HERE
#endif
#define int long long
#define f first
#define s second
#define pii pair<int, int>
#define FOR(a, b, c) for (int(a) = (b); (a) < (c); ++(a))
#define FORN(a, b, c) for (int(a) = (b); (a) <= (c); ++(a))
#define FORR(a, b, c) for (int(a) = (b); (a) >= (c); --(a))
#define ALLV(v) v.begin(), v.end()
#define ALLA(arr, sz) arr, arr + sz
#define SORT(v) sort(ALL(v))
#define REVERSE(v) reverse(ALL(v))
#define SORTA(arr, sz) sort(ALLA(arr, sz))
#define REVERSEA(arr, sz) reverse(ALLA(arr, sz))
template <typename A, typename B> ostream& operator<<(ostream& out, const pair<A, B>& a) { out << "(" << a.first << ", " << a.second << ")"; return out; }
template<typename ...Ts, size_t ...Is> ostream& println_tuple_impl(ostream& os, tuple<Ts...> tuple, index_sequence<Is...>) { static_assert(sizeof...(Is) == sizeof...(Ts), "Indices must have same number of elements as tuple types!"); static_assert(sizeof...(Ts) > 0, "Cannot insert empty tuple into stream."); auto last = sizeof...(Ts) - 1; os << "("; return ((os << get<Is>(tuple) << (Is != last ? ", " : ")\n")), ...); }
template<typename ...Ts> ostream& operator<<(ostream& os, const tuple<Ts...>& tuple) { return println_tuple_impl(os, tuple, index_sequence_for<Ts...>{}); }
int N, R, G, Y;
map<tuple<int, int, int, int>, int> memo;
vector<int> rPos, gPos, yPos;
string S;
int dp(int RR, int GG, int YY, int lastUsed) {
if (memo.find({ RR, GG, YY, lastUsed }) != memo.end())
return memo[{RR, GG, YY, lastUsed}];
if (RR == R && GG == G && YY == Y) return 0;
int res = 1e18, idx = RR + GG + YY;
if (RR < R && lastUsed != 0) {
int nearestR = rPos[RR];
res = min(res, dp(RR + 1, GG, YY, 0) + abs(nearestR - idx));
}
if (GG < G && lastUsed != 1) {
int nearestG = gPos[GG];
res = min(res, dp(RR, GG + 1, YY, 1) + abs(nearestG - idx));
}
if (YY < Y && lastUsed != 2) {
int nearestY = yPos[YY];
res = min(res, dp(RR, GG, YY + 1, 2) + abs(nearestY - idx));
}
memo[{RR, GG, YY, lastUsed}] = res;
return res;
}
int32_t main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
cin >> N >> S;
FOR(i, 0, N) {
if (S[i] == 'R') {
R++;
rPos.push_back(i);
}
if (S[i] == 'G') {
G++;
gPos.push_back(i);
}
if (S[i] == 'Y') {
Y++;
yPos.push_back(i);
}
}
int res = dp(0, 0, 0, -1);
//if (res >= 1e18) cout << -1;
else cout << res / 2;
}
Compilation message
joi2019_ho_t3.cpp: In function 'int32_t main()':
joi2019_ho_t3.cpp:28:34: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
28 | #define FOR(a, b, c) for (int(a) = (b); (a) < (c); ++(a))
| ^
joi2019_ho_t3.cpp:76:9: note: in expansion of macro 'FOR'
76 | FOR(i, 0, N) {
| ^~~
joi2019_ho_t3.cpp:92:9: error: 'else' without a previous 'if'
92 | else cout << res / 2;
| ^~~~
