美团笔试编程题交流

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

int main()
{
    long n;
    while(cin >> n)
    {
			int ai;
			bool flag;
			int cnt = 0;
			vector<int> lamp;
			for(int i =0; i <n; ++i){
				cin >> ai;
				lamp.push_back(ai);
			}
			
			flag = lamp[0];
			
			for(int i =1; i <n; ++i){
				if(lamp[i] == flag){
					continue;
				}else{
					++cnt;
					flag = lamp[i];
				}
			}
			
			if((lamp[0] ==1) && (cnt & 1) || (lamp[0] ==0) && !(cnt & 1))
				cout << "Bob" <<endl;
			else
				cout << "Alice" <<endl;

    }
    return 0;
}

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

long long combine2Num(long long n1, long long n2){
	int bit = 0;
	long long t = n2;
	while(n2/10){
		++bit;
		n2 /= 10;
		n1 *= 10; 
	}
	n1 *= 10; 
	return n1 + t;
}

int main()
{
    int n;
    while(cin >> n)
    {
			int ret = 0;
			int ai;
			int nn = 0;
			vector<long long> a;
			bool is7n[n];
			for(int i =0; i <n; ++i){
				cin >> ai;
				a.push_back(ai);
			}
			
			for(int i = 0; i < n;++i){
				if(a[i] % 7 == 0){
					is7n[i] = true;
					++nn;
				}
				else
					is7n[i] = false;
			}

			ret = nn*(nn-1);
			for(int i = 0 ;i < n;++i){
				if(is7n[i]){
						continue;
				}
				for(int j = i+1; j < n; ++j){				
					if(is7n[j]){
              continue;
          }					
					if( (combine2Num(a[i],a[j]) % 7) == 0){						
						++ret;
					}
					if( (combine2Num(a[j],a[i]) % 7) == 0){
						++ret;
					}
				}
			}
			cout <<ret<<endl;
    }
    return 0;
}
求各位大佬的思路啊~~~