#include<bits/stdc++.h> using namespace std; // define #define execute cerr << " Time: " << fixed << setprecision(6) << (1.0 * clock() / CLOCKS_PER_SEC) << "s\n"; #define ll long long #define ii pair <int , int> #define iii pair <int , ii> #define se second #define fi first #define all(v) (v).begin() , (v).end() #define Unique(v) sort(all(v)) , v.resize(unique(all(v)) - v.begin()) #define bit(x,i) (((x) >> (i)) & 1LL) #define flip(x,i) ((x) ^ (1LL << (i))) #define ms(d,x) memset(d , x , sizeof(d)) #define exist __exist #define ends __ends #define visit visited #define left __left #define right __right #define prev __prev #define next __next #define sitingfake 1 #define orz 1 //constant const long long mod = 1e9 + 7; const long long linf = 4557430888798830399LL; const long long nlinf = -4485090715960753727LL; const int LOG = 20; const int inf = 1061109567; const int ninf = -1044266559; const int dx[] = {0 , -1 , 0 , 1}; const int dy[] = {-1 , 0 , 1 , 0}; template<typename T> bool maximize(T &a, const T &b) { if(a < b) {a = b; return 1;} return 0; } template<typename T> bool minimize(T &a, const T &b) { if(a > b) {a = b; return 1;} return 0; } void Plus(ll & a ,ll b) { b %= mod; a += b; if(a < 0) a += mod; a %= mod; return; } void Mul(ll & a, ll b) { (a *= (b % mod)) %= mod; return; } //code const int maxn = 1e6 + 7; int a[maxn] , b[maxn]; string s; int n , k; int timerA , timerB; namespace sub3 { ll dp[505][505]; ll pref[550]; ll sum(int l , int r) { return 1ll * ((r * (r + 1)) / 2) - 1ll * ((l * (l - 1)) / 2); } ll cost(int l , int r) { if(a[l] < b[l]) { int pos = upper_bound(a + 1 , a + n + 1 , b[l]) - a; return pref[r] - pref[pos - 1] - sum(b[l] , b[l] + (r - pos)); } else { int pos = upper_bound(b + 1 , b + n + 1 , a[l]) - b - 1; int len = pos - l + 1; return pref[r] - pref[l - 1] - sum(a[l] - len , a[l] - len + (r - l)); } } void solve() { for(int i = 1; i <= n; i++) { pref[i] += pref[i - 1] + a[i]; } ms(dp , 0x3f); dp[0][0] = 0; for(int i = 1; i <= k; i++) { for(int j = i; j <= n; j++) { for(int t = j; t >= 1; t--) { minimize(dp[i][j] , dp[i - 1][t - 1] + cost(t , j)); } } } cout << dp[k][n]; } } void solve(void) { cin >> n >> k; cin >> s; for(int i = 0; i < s.size(); i++) { if(s[i] == 'A') a[++timerA] = i; else b[++timerB] = i; } if(n <= 500) sub3 :: solve(); } /** 3 1 BBBAAA **/ signed main() { ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); #define task "" if(fopen(task".inp","r")) { freopen(task".inp","r",stdin); freopen(task".out","w",stdout); } int tc = 1; // cin >> tc; while(tc--) solve(); // execute; }

chorus.cpp: In function 'int main()':
chorus.cpp:144:15: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  144 |        freopen(task".inp","r",stdin);
      |        ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
chorus.cpp:145:15: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  145 |        freopen(task".out","w",stdout);
      |        ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~