'commit'

TangDou/CSP-J/J2-2021/AcWing1221_ManualHash.cpp

@@ -0,0 +1,38 @@
+#include <cstdio>
+#include <cstring>
+#include <algorithm>
+#include <cmath>
+/*
+用桶计数的思路
+*/
+// Accepted	134 ms
+using namespace std;
+const int N = 5e6 + 10;
+int n;
+int bucket[N];
+
+int main() {
+    scanf("%d", &n);
+
+    memset(bucket, -1, sizeof bucket);
+
+    for (int c = 0; c * c <= n / 2; c++)
+        for (int d = c; c * c + d * d <= n; d++) {
+            int t = c * c + d * d;
+            if (t > 5e6) continue;
+            if (bucket[t] == -1) bucket[t] = c;
+        }
+
+    for (int a = 0; a * a <= n / 4; a++) {
+        for (int b = a; a * a + b * b <= n / 3; b++) {
+            int t = n - a * a - b * b;
+            int c = bucket[t];
+            if (c == -1 || t > 5e6) continue;
+            int d = sqrt(t - c * c);
+            printf("%d %d %d %d\n", a, b, c, d);
+            exit(0);
+        }
+    }
+
+    return 0;
+}