#include <bits/stdc++.h> using namespace std; const int N = 8005; const int K = 8005; int dp[N][K][2]; int pref[N]; void count_pref(int n, string seg) { for (int i = 1; i <= n; i++) { pref[i] = pref[i - 1]; if (seg[i - 1] != '3') pref[i]++; } return; } void prepare(int n, int k) { for (int j = 0; j <= n; j++) { for (int i = 0; i <= k; i++) { dp[j][i][0] = dp[j][i][1] = -1; } } dp[0][0][0] = 0; dp[0][0][1] = -1; return; } void solve(int n, int k, int t, string seg) { for (int i = 1; i <= n; i++) { for (int j = 0; j <= k; j++) { bool house = (seg[i - 1] != '1'); if (house) dp[i][j][0] = dp[i - 1][j][0]; dp[i][j][1] = dp[i - 1][j][1]; if (i - t - 1 >= 0 && j - (pref[i - 1] - pref[i - t - 1]) >= 0) { dp[i][j][1] = max(dp[i][j][1], dp[i - t - 1][j - (pref[i - 1] - pref[i - t - 1])][0]); } if (house) { int x = (seg[i - 1] == '3') ? 1 : 0; dp[i][j][0] = max(dp[i][j][0], dp[i - 1][j][0] + x); if (i - t - 1 >= 0 && j - (pref[i - 1] - pref[i - t - 1]) >= 0) { dp[i][j][0] = max(dp[i][j][0], dp[i - t - 1][j - (pref[i - 1] - pref[i - t - 1])][1] + x); } if (seg[i - 1] == '2' && j > 0) { dp[i][j][0] = max(dp[i][j][0], dp[i - 1][j - 1][0] + 1); if (i - t - 1 >= 0 && j - (pref[i - 1] - pref[i - t - 1]) - 1 >= 0) { dp[i][j][0] = max(dp[i][j][0], dp[i - t - 1][j - (pref[i - 1] - pref[i - t - 1]) - 1][1] + 1); } } } else { if (j > 0) { dp[i][j][0] = max(dp[i][j][0], dp[i - 1][j - 1][0] + 1); if (i - t - 1 >= 0 && j - (pref[i - 1] - pref[i - t - 1]) - 1 >= 0) { dp[i][j][0] = max(dp[i][j][0], dp[i - t - 1][j - (pref[i - 1] - pref[i - t - 1] - 1)][1] + 1); } } } } } return; } void ans(int n, int k) { int res = -1; for (int i = 0; i <= k; i++) { res = max(res, dp[n][i][0]); } cout << res << endl; return; } int main() { cin.tie(0) -> sync_with_stdio(false); int n, k, t; string s; cin >> n >> k >> t; cin >> s; count_pref(n, s); prepare(n, k); solve(n, k, t, s); ans(n, k); return 0; }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 | #include <bits/stdc++.h> using namespace std; const int N = 8005; const int K = 8005; int dp[N][K][2]; int pref[N]; void count_pref(int n, string seg) { for (int i = 1; i <= n; i++) { pref[i] = pref[i - 1]; if (seg[i - 1] != '3') pref[i]++; } return; } void prepare(int n, int k) { for (int j = 0; j <= n; j++) { for (int i = 0; i <= k; i++) { dp[j][i][0] = dp[j][i][1] = -1; } } dp[0][0][0] = 0; dp[0][0][1] = -1; return; } void solve(int n, int k, int t, string seg) { for (int i = 1; i <= n; i++) { for (int j = 0; j <= k; j++) { bool house = (seg[i - 1] != '1'); if (house) dp[i][j][0] = dp[i - 1][j][0]; dp[i][j][1] = dp[i - 1][j][1]; if (i - t - 1 >= 0 && j - (pref[i - 1] - pref[i - t - 1]) >= 0) { dp[i][j][1] = max(dp[i][j][1], dp[i - t - 1][j - (pref[i - 1] - pref[i - t - 1])][0]); } if (house) { int x = (seg[i - 1] == '3') ? 1 : 0; dp[i][j][0] = max(dp[i][j][0], dp[i - 1][j][0] + x); if (i - t - 1 >= 0 && j - (pref[i - 1] - pref[i - t - 1]) >= 0) { dp[i][j][0] = max(dp[i][j][0], dp[i - t - 1][j - (pref[i - 1] - pref[i - t - 1])][1] + x); } if (seg[i - 1] == '2' && j > 0) { dp[i][j][0] = max(dp[i][j][0], dp[i - 1][j - 1][0] + 1); if (i - t - 1 >= 0 && j - (pref[i - 1] - pref[i - t - 1]) - 1 >= 0) { dp[i][j][0] = max(dp[i][j][0], dp[i - t - 1][j - (pref[i - 1] - pref[i - t - 1]) - 1][1] + 1); } } } else { if (j > 0) { dp[i][j][0] = max(dp[i][j][0], dp[i - 1][j - 1][0] + 1); if (i - t - 1 >= 0 && j - (pref[i - 1] - pref[i - t - 1]) - 1 >= 0) { dp[i][j][0] = max(dp[i][j][0], dp[i - t - 1][j - (pref[i - 1] - pref[i - t - 1] - 1)][1] + 1); } } } } } return; } void ans(int n, int k) { int res = -1; for (int i = 0; i <= k; i++) { res = max(res, dp[n][i][0]); } cout << res << endl; return; } int main() { cin.tie(0) -> sync_with_stdio(false); int n, k, t; string s; cin >> n >> k >> t; cin >> s; count_pref(n, s); prepare(n, k); solve(n, k, t, s); ans(n, k); return 0; } |