Add 02315.cpp

02xxx/02315.cpp

@@ -0,0 +1,36 @@
+#include <algorithm>
+#include <iostream>
+#include <vector>
+using namespace std;
+
+void solve(void) {
+  int n, m; cin >> n >> m;
+  vector<long long> d(1001, 0), w(1001, 0);
+  for (int i=1; i<=n; i++) cin >> d[i] >> w[i];
+  for (int i=1; i<=n; i++) w[i] += w[i-1];
+
+  vector<vector<long long>> dp1(1001, vector<long long>(1001, 0)), dp2(1001, vector<long long>(1001, 0));
+  for (int l=2; l<=m; l++) {
+    dp1[l][n] = dp1[l-1][n] + w[l-1] * (d[l]-d[l-1]);
+    dp2[l][n] = dp1[l-1][n] + w[l-1] * (d[n]-d[l-1]);
+  }
+  for (int r=n-1; r>=m; r--) {
+    dp1[1][r] = dp2[1][r+1] + (w[n]-w[r]) * (d[r+1]-d[1]);
+    dp2[1][r] = dp2[1][r+1] + (w[n]-w[r]) * (d[r+1]-d[r]);
+  }
+  for (int l=2; l<=m; l++) {
+    for (int r=n-1; r>=m; r--) {
+      dp1[l][r] = min(dp1[l-1][r] + (w[n]-w[r]+w[l-1]) * (d[l]-d[l-1]), dp2[l][r+1] + (w[n]-w[r]+w[l-1]) * (d[r+1]-d[l]));
+      dp2[l][r] = min(dp1[l-1][r] + (w[n]-w[r]+w[l-1]) * (d[r]-d[l-1]), dp2[l][r+1] + (w[n]-w[r]+w[l-1]) * (d[r+1]-d[r]));
+    }
+  }
+  cout << min(dp1[m][m], dp2[m][m]);
+}
+
+int main(void) {
+  ios::sync_with_stdio(false);
+  cin.tie(nullptr);
+
+  solve();
+  return 0;
+}