牛客网程序题

腾讯2018春招技术类编程题

第一题

#include<iostream>
using namespace std;

long Sum_arr(long n,long m)
{
    long Sum=0;
    for(long i=1;i<=m;i++)
    {
        long flag=-1;
        for(long j=i;j<=n;j+=m)
        {
            Sum+=j*flag;
            flag=-flag;
        }
    }
    return Sum;
}

int main()
{
    long n,m;
    cin>>n>>m;
    while(!(n>=2&&n<=(1e9)&&m>=1&&(n%(2*m))==0))
        cin>>n>>m;
    cout<<Sum_arr(n,m)<<endl;
    return 0;
}

 第二题(有误）

#include<iostream>
#include<vector>
using namespace std;

void sort(vector<long> &aa, long p)
{
    for (long i = 0; i<p; i++)
    {
        long k=i;
        for (long j = i; j<p; j++)
        {
            if (aa[i]<aa[j])
                k=j;
        }
        swap(aa[i], aa[k]);
    }
}

long Fun(vector<long> arr, long n)
{
    sort(arr, n);
    long sum1 = 0, sum2 = 0;//sum1 牛牛
    for (long i = 0; i<n; i += 2)
        sum1 += arr[i];
    for (long i = 1; i<n; i += 2)
        sum2 += arr[i];
    return sum1 - sum2;
}

int main()
{
    long n;
    cin >> n;
    vector<long> arr(n);
    for (long i = 0; i<n; i++)
        cin >> arr[i];
    cout << Fun(arr, n)<< endl;
    return 0;
}