Update: Rename folder name to XSMOJ

XSMOJ/小码君的阶段求和.cpp

@@ -0,0 +1,26 @@
+#include <algorithm>
+#include <iostream>
+#include <iomanip>
+#include <cstring>
+#include <cstdio>
+#include <stack>
+#include <ctime>
+#include <cmath>
+#include <queue>
+typedef long long l;
+typedef double d;
+typedef char c;
+using namespace std;
+int s(int a,int b,int c){
+	int sum=0;
+	for(int i=a;i<=b;i+=c){
+		sum+=i;
+	}
+	return sum;
+}
+int main(){
+	int a,b,c;
+	cin >>a>>b>>c;
+	cout <<fixed<<setprecision(3)<<s(a,b*10,c)*1.0/(s(a,b*2,c*1.0/2)*s(a*1.0/2,b-a,c*2));
+	return 0;
+}