new file: P2280.cpp

P2280.cpp

@@ -0,0 +1,41 @@
+// 101
+#include <cstdio>
+#include <algorithm>
+using namespace std;
+int n, r;
+int maxx = 0, maxy = 0;
+int sum[5005][5005];
+int query(int i, int j)
+{
+    int x2 = min(maxx, i + r - 1);
+    int y2 = min(maxy, j + r - 1);
+    return sum[x2][y2] - sum[i - 1][y2] - sum[x2][j - 1] + sum[i - 1][j - 1];
+}
+int main()
+{
+    scanf("%d%d", &n, &r);
+    for (int x, y, w, i = 1; i <= n; ++i)
+        scanf("%d%d%d", &x, &y, &w), maxx = max(maxx, x+1), maxy = max(maxy, y+1), sum[x+1][y+1] += w;
+    for (int i = 1; i <= maxx; ++i)
+    {
+        for (int j = 1; j <= maxy; ++j)
+        {
+            sum[i][j] += sum[i - 1][j] + sum[i][j - 1] - sum[i - 1][j - 1];
+        }
+    }
+    if (r >= maxx && r >= maxy)
+    {
+        printf("%d\n", sum[maxx][maxy]);
+        return 0;
+    }
+    int ans = 0;
+    for (int i = 1; i <= maxx; ++i)
+    {
+        for (int j = 1; j <= maxy; ++j)
+        {
+            ans = max(ans, query(i, j));
+        }
+    }
+    printf("%d\n", ans);
+    return 0;
+}