codes: dp'

Author: MorettiGS

codes/DP/kadane.cpp

@@ -0,0 +1,9 @@
+int kadane(const vector<int>& as) {
+    vector<int> s(as.size());
+    s[0] = as[0];
+
+    for (size_t i = 1; i < as.size(); ++i)
+        s[i] = max(as[i], s[i - 1] + as[i]);
+
+    return *max_element(s.begin(), s.end());
+}

codes/DP/lis.cpp

@@ -0,0 +1,12 @@
+int LIS(int N, const vector<int>& as) {
+    vector<int> lis(N + 1, oo);
+    lis[0] = -oo;
+    auto ans = 0;
+    for (int i = 0; i < N; ++i) {
+        auto it = lower_bound(lis.begin(), lis.end(), as[i]);
+        auto pos = (int) (it - lis.begin());
+        ans = max(ans, pos);
+        lis[pos] = as[i];
+    }
+    return ans;
+}

codes/DP/max2dRS-K.cpp

@@ -0,0 +1,22 @@
+int kadane(int N, const vector<int>& as) {
+    vector<int> s(N + 1);
+    s[1] = as[1];
+    for (size_t i = 2; i < as.size(); ++i)
+        s[i] = max(as[i], s[i - 1] + as[i]);
+    return *max_element(s.begin() + 1, s.end());
+}
+
+int MSR(int N, int M, const vector<vector<int>>& A) {
+    int ans = -oo;
+    for (int i = 1; i <= M; ++i) {
+        vector<int> r(N + 1, 0);
+
+        for (int j = i; j <= M; ++j) {
+            for (int k = 1; k <= N; ++k)
+                r[k] += A[k][j]; 
+
+            ans = max(ans, kadane(N, r));
+        }
+    }
+    return ans;
+}

codes/DP/maxRS-PS.cpp

@@ -0,0 +1,15 @@
+long long MRS(const vector<int>& as)
+{
+    auto N = as.size() - 1;
+    vector<long long> ps(N + 1, 0);
+    // O código assume que os índices da sequência as começam em 1
+    for (size_t i = 1; i <= N; ++i)
+        ps[i] = ps[i - 1] + as[i];
+
+    long long ans = -oo;
+    for (size_t i = 1; i <= N; ++i)
+        for (size_t j = i; j <= N; ++j)
+            ans = max(ans, ps[j] - ps[i - 1]);
+
+    return ans;
+}

codes/DP/maxSSM.cpp

@@ -0,0 +1,16 @@
+int A[MAX][MAX], S[MAX][MAX];
+int MSS(int N, int M) {
+    for (int i = 0; i < N; ++i)
+        S[i][0] = A[i][0];
+    for (int j = 0; j < M; ++j)
+        S[0][j] = A[0][j];
+
+    int ans = 0;
+    for (int i = 1; i < N; ++i)
+        for (int j = 1; j < M; ++j) {
+            S[i][j] = A[i][j] == 0 ? 0 : min({ S[i-1][j], S[i][j-1], S[i-1][j-1] }) + 1;
+
+            ans = max(ans, S[i][j]);
+        }
+    return ans;
+}

codes/DP/tsp.cpp

@@ -0,0 +1,13 @@
+int dist[MAX][MAX];
+int st[MAX][1 << MAX];
+int tsp(int i, int mask, int N) {
+    if (mask == (1 << N) - 1) return dist[i][0];
+    if (st[i][mask] != -1) return st[i][mask];
+    int res = oo;
+    for (int j = 0; j < N; ++j) {
+        if (mask & (1 << j)) continue;
+
+        res = min(res, tsp(j, mask | (1 << j), N) + dist[i][j]);
+    }
+    return (st[i][mask] = res);
+}