Codeforces-solutions/J. Journey To Stringland/J. Journey To Stringland.cpp
2025-09-12 14:50:25 -03:00

114 lines
2.4 KiB
C++

/* Problem URL: https://codeforces.com/problemset/gymProblem/105164/J */
#include <bits/stdc++.h>
using namespace std;
#define V vector
#define rmin(a, b) a = min(a, b)
#define rmax(a, b) a = max(a, b)
#define rep(i, lim) for (int i = 0; i < (lim); i++)
#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
#define repv(i, v) for (auto &i : (v))
#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
#define sortv(v) sort(v.begin(), v.end())
#define all(v) (v).begin(), (v).end()
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using vvvvi = vector<vvvi>;
using ll = long long;
using vl = vector<ll>;
using vvl = vector<vl>;
using vvvl = vector<vvl>;
using vvvvl = vector<vvvl>;
template<class v>
auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
os << vec[0];
for (size_t i = 1; i < vec.size(); i++) {
os << ' ' << vec[i];
}
os << '\n';
return os;
}
template<class v>
auto operator>>(istream &is, vector<v> &vec)->istream& {
for (auto &i : vec) {
is >> i;
}
return is;
}
template<class v>
auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
for (auto &i : vec) {
os << i[0];
for (size_t j = 1; j < i.size(); j++) {
os << ' ' << i[j];
}
os << '\n';
}
return os;
}
template<class v>
auto operator>>(istream &is, vector<vector<v>> &vec)->istream& {
for (auto &i : vec) {
for (auto &j : i) {
is >> j;
}
}
return is;
}
int main()
{
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n, k;
cin >> n >> k;
string fds;
cin >> fds;
int inf = INT32_MAX >> 1;
vvvi dp(n, vvi(k + 1, vi(n, inf)));
dp[0][0][0] = 0;
dp[0][1][0] = 0;
nrep(i, 1, n) {
fill(all(dp[i][0]), 0);
fill(all(dp[i][1]), 0);
if (k >= 2) {
for (int j = i - 1; j >= 0; j--) {
dp[i][2][j] = fds[i] != fds[j];
}
}
for (int j = i - 2; j >= 0; j--) {
for (int l = 2; l <= k; l++) {
dp[i][l][j] = dp[i - 1][l][j];
rmin(dp[i][l][j], dp[i - 1][l - 2][j + 1] + (fds[i] != fds[j]));
rmin(dp[i][l][j], dp[i][l][j + 1]);
}
}
}
// for (auto &i : dp) {
// cout << i;
// cout << "------------------------------\n";
// }
cout << *min_element(all(dp[n - 1][k])) << '\n';
}