PTA 估值一亿的AI核心代码 （STL：各种string）_估值一亿的ai核心代码pta

L1-064 估值一亿的AI核心代码 （20 分)

分析：

问题极为复杂就划分为7个小问题，分别进行求解操作，过程中用到了string头文件中的erase，replace，find，rfind等多个函数，STL的使用可以较好简化代码。

代码：

#include <bits/stdc++.h>
using namespace std;
int main()
{
	int n;
	cin >> n;
	getchar();
	while (n--)
	{
		string s;
		getline(cin, s);
 
		//1)
		cout << s << endl;
 
		//2)
		while (s[0] == ' ')s.erase(s.begin());
		while (s[s.length() - 1] == ' ')s.erase(s.end() - 1);
		for (int i = 0; i<s.length(); i++)
		{
			if (s[i] == ' ')
			{
				while (s[i + 1] == ' ')s.erase(s.begin() + i + 1);
				if (s[i + 1]<'0' || s[i + 1]>'9'&&s[i + 1]<'A' || s[i + 1]>'Z'&&s[i + 1]<'a' || s[i + 1]>'z')
				{
					s.erase(s.begin() + i);
				}
			}
		}
 
		//3)
		for (int i = 0; i<s.length(); i++)
		{
			if (s[i] >= 'A'&&s[i] <= 'Z'&&s[i] != 'I')s[i] -= 'A' - 'a';
		}
 
		//4)
		for (int beg = 0;; beg++)
		{
			beg = s.find("can you", beg);
			if (beg == -1)break;
			if ((beg == 0 || s[beg - 1]<'0' || s[beg - 1]>'9'&&s[beg - 1]<'A' || s[beg - 1]>'Z'&&s[beg - 1]<'a' || s[beg - 1]>'z') && (beg + 7 == s.length() || s[beg + 7]<'0' || s[beg + 7]>'9'&&s[beg + 7]<'A' || s[beg + 7]>'Z'&&s[beg + 7]<'a' || s[beg + 7]>'z'))
			{
				s.replace(beg, 7, "A can");
			}
		}
		for (int beg = 0;; beg++)
		{
			beg = s.find("could you", beg);
			if (beg == -1)break;
			if ((beg == 0 || s[beg - 1]<'0' || s[beg - 1]>'9'&&s[beg - 1]<'A' || s[beg - 1]>'Z'&&s[beg - 1]<'a' || s[beg - 1]>'z') && (beg + 9 == s.length() || s[beg + 9]<'0' || s[beg + 9]>'9'&&s[beg + 9]<'A' || s[beg + 9]>'Z'&&s[beg + 9]<'a' || s[beg + 9]>'z'))
			{
				s.replace(beg, 9, "A could");//由于后面还要处理'I'这里先用'A'代替'I'，最后在变成'I'
			}
		}
 
		//5)
		for (int beg = 0;; beg++)
		{
			beg = s.find("I", beg);
			if (beg == -1)break;
			if ((beg == 0 || s[beg - 1]<'0' || s[beg - 1]>'9'&&s[beg - 1]<'A' || s[beg - 1]>'Z'&&s[beg - 1]<'a' || s[beg - 1]>'z') && (beg + 1 == s.length() || s[beg + 1]<'0' || s[beg + 1]>'9'&&s[beg + 1]<'A' || s[beg + 1]>'Z'&&s[beg + 1]<'a' || s[beg + 1]>'z'))
			{
				s.replace(beg, 1, "you");
			}
		}
		for (int beg = 0;; beg++)
		{
			beg = s.find("me", beg);
			if (beg == -1)break;
			if ((beg == 0 || s[beg - 1]<'0' || s[beg - 1]>'9'&&s[beg - 1]<'A' || s[beg - 1]>'Z'&&s[beg - 1]<'a' || s[beg - 1]>'z') && (beg + 2 == s.length() || s[beg + 2]<'0' || s[beg + 2]>'9'&&s[beg + 2]<'A' || s[beg + 2]>'Z'&&s[beg + 2]<'a' || s[beg + 2]>'z'))
			{
				s.replace(beg, 2, "you");
			}
		}
 
		//6)
		for (int i = 0; i<s.length(); i++)
		{
			if (s[i] == '?')s[i] = '!';
			if (s[i] == 'A')s[i] = 'I';
		}
 
		//7)
		cout << "AI: " << s << endl;
	}
	return 0;
}