CodeForces - 598A Tricky Sum
题目描述:
In this problem you are to calculate the sum of all integers from 1 to n, but you should take all powers of two with minus in the sum.
For example, for n = 4 the sum is equal to - 1 - 2 + 3 - 4 = - 4, because 1, 2 and 4 are 20, 21 and 22 respectively.
Calculate the answer for t values of n.
Input
The first line of the input contains a single integer t (1 ≤ t ≤ 100) — the number of values of n to be processed.
Each of next t lines contains a single integer n (1 ≤ n ≤ 109).
Output
Print the requested sum for each of t integers n given in the input.
Examples
Input
2
4
1000000000
Output
-4
499999998352516354
Note
The answer for the first sample is explained in the statement.
题目大意:给出一个数n,从1运算到n,如果这个数是2的倍数,就为减,否则就为加。
思路:这道题。。。其实就是等差数列、等比数列求和。但是注意是减去两倍的等比数列。
#include <iostream>
#include <cctype>
#include <algorithm>
#include <cmath>
#include <cstdio>
#include <cstdlib>
using namespace std;
int t;
long long ans , n , i;
int main(){
scanf("%d",&t);
while(t--){
i = 1;
scanf("%lld",&n);
ans = (n * (n + 1)) / 2;
while(i <= n) i = i * 2;
ans = ans - i * 2 + 2;
printf("%lld\n",ans);
}
return 0;
}