'commit'

TangDou/XiTi/1426.cpp

@@ -0,0 +1,15 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+int main() {
+    // 15 3 4
+    int n, a, b;
+    cin >> n >> a >> b;
+    n -= a * (b - 1);
+    n--, a--;
+    int x = 1, y = 1;
+    for (int i = n; i > n - a; i--) x *= i;
+    for (int i = a; i; i--) y *= i;
+    printf("%d\n", x / y);
+    return 0;
+}