lightoj（基础数学）

点击题目链接

/*****************************************
Author      :Crazy_AC(JamesQi)
Time        :2015
File Name   :
*****************************************/
// #pragma comment(linker, "/STACK:1024000000,1024000000")
#include <iostream>
#include <algorithm>
#include <iomanip>
#include <sstream>
#include <string>
#include <stack>
#include <queue>
#include <deque>
#include <vector>
#include <map>
#include <set>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <stdlib.h>
#include <limits.h>
using namespace std;
#define MEM(a,b) memset(a,b,sizeof a)
typedef long long LL;
typedef unsigned long long ULL;
typedef pair<int,int> ii;
const int inf = 1 << 30;
const int INF = 0x3f3f3f3f;
const int MOD = 1e9 + 7;
int main()
{	
	// freopen("in.txt","r",stdin);
	// freopen("out.txt","w",stdout);
	int num,n;
	LL kase = 0;
	cin >> num;
	while(num--){
		LL res = 0;
		kase++;
		cin >> n;
		LL t1,t2;
		for (LL i = 1;i <= n;i = t2 + 1){
			t1 = n / i;
			t2 = n / t1;
			res += (LL)t1 * (t2 - i + 1);
		}
		printf("Case %lld: %lld\n",kase,res);
	}
	return 0;
}