今日头条2017后端工程师笔试题

#include<iostream> 
#include<vector> 
#include<string> 
#include<algorithm> 
#include<numeric>    //数值算法
using namespace std;

//节点类：每个字符对应一个权重 
struct Node
{
	char ch;
	long long num;
	Node() {}       //默认构造函数
	Node(char c, int n) :ch(c), num(n)
	{
	}
};

//按照权重对节点进行排序 
bool cmp(const Node &a, const Node &b)
{
	return a.num < b.num;
}

//取得每个字符的权重 
void getWeight(vector<string> &data, vector<Node> &arr)
{
	for (int i = 0; i < data.size(); ++i)
	{
		long long index = 1;
		for (int j = data[i].size() - 1; j >= 0; --j)
		{
			int pos = data[i][j];
			arr[pos - ‘A‘].num += index;
			index *= 10;
		}
	}
}

int main()
{
	int n;
	while (cin >> n)
	{
		string str;
		//字符串集合 
		vector<string> data(n);
		for (int i = 0; i < n; ++i)
		{
			cin >> str;
			data[i] = str;
		}
		//节点类集合 
		vector<Node> arr(10);
		for (int i = ‘A‘; i <= ‘J‘; ++i)
		{
			arr[i - ‘A‘] = Node(i, 0);
		}
		//计算每个字符的权重 
		getWeight(data, arr);
		//按照权重由小到大进行排序 
		sort(arr.begin(), arr.end(), cmp);
		//每个字符是否在字符串首位置出现过（1:出现过） 
		vector<int> flag(10, 0);
		for (int i = 0; i < n; ++i)
		{
			flag[data[i][0] - ‘A‘] = 1;
		}
		//在排序数组中，第一个没有在字符串首位置出现的字符的位置 
		int spec_pos = 0;
		for (; spec_pos < 10; ++spec_pos)
		{
			if (flag[arr[spec_pos].ch - ‘A‘] == 0)
				break;
		}
		Node tmp = arr[spec_pos];
		//向后移动一位，把spec_pos位置的元素放在首部 
		for (int i = spec_pos; i > 0; --i)
		{
			arr[i] = arr[i - 1];
		}
		arr[0] = tmp;
		//将0~9赋值给相应的字符 
		vector<int> numArr(10);
		for (int i = 0; i < 10; ++i)
		{
			numArr[arr[i].ch - ‘A‘] = i;
		}
		//字符串集合转换为整型数集合 
		vector<long long> num(n);
		for (int i = 0; i < n; ++i)
		{
			long long val = 0;
			long long index = 1;
			for (int j = data[i].size() - 1; j >= 0; --j)
			{
				val += numArr[data[i][j] - ‘A‘] * index;
				index *= 10;
			}
			num[i] = val;
		}
		long long count = 0;
		//对整型数集合求值 
		cout << accumulate(num.begin(), num.end(), count) << endl;
	}

	return 0;
}