目录调整

00lanqiao chap/test99-4-3.cpp

@@ -0,0 +1,39 @@
+// 蓝桥3075 特殊的多边形
+#include<bits/stdc++.h>
+using namespace std;
+const int N = 1e5+9;
+int n, cnt[N], prefix[N];
+
+void dfs(int dep, int st, int mul, int sum){
+    // 剪枝1
+    if(mul > 1e5) return;
+    if(dep == n + 1){
+        cnt[mul]++; 
+        return;
+    }
+    // 剪枝2
+    int up = pow(1e5 / mul, 1.0/(n - dep + 1)) + 3;
+    for(int i = st + 1; i < (dep == n?min(sum, up):up); i++){
+        dfs(dep+1, i, mul * i, sum + i);
+    }
+}
+
+int main(){
+    int q; cin >> q >> n;
+    dfs(1, 0, 1, 0);
+    for(int i = 1; i <= 1e5; i++){
+        prefix[i] = prefix[i-1] + cnt[i];
+    }
+    while(q--){
+        int l, r; cin >> l >> r;
+        cout << prefix[r] - prefix[l-1] << '\n';
+    }
+    return 0;
+}
+/* test samples
+4 3
+1 10
+30 50
+60 200
+200 400
+*/