一、视频讲解

蓝桥杯真题讲解：填充（贪心）

二、正解代码

//填充：贪心
#include<bits/stdc++.h>
#define endl '\n'
#define deb(x) cout << #x << " = " << x << '\n';
#define INF 0x3f3f3f3f
using namespace std;

void solve()
{
	string s; cin >> s;
	vector<bool>st(s.size());//记录i位置是否匹配过
	int ans = 0;
	for(int i = 0; i < s.size(); i ++)
	{
		if(s[i] != '?')
		{
			if(!st[i])
			{
				if(i - 1 >= 0 and s[i - 1] == s[i] and !st[i - 1])
				{
					st[i - 1] = true;
					st[i] = true;
					ans ++;
				}
				else if(i + 1 < s.size() and s[i + 1] == s[i] and !st[i + 1])
				{
					st[i] = true;
					st[i + 1] = true;
					ans ++;
				}
				
			}
		}
		else
		{
			if(st[i])
				continue;
			
			if(i - 1 >= 0 and !st[i - 1])
			{
				st[i] = true;
				st[i - 1] = true;
				ans ++;
			}
			else if(i + 1 < s.size() and !st[i + 1])
			{
				st[i] = true;
				st[i + 1] = true;
				ans ++;
			}
		}
	}
	cout << ans << endl;
}

signed main()
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	int t;
	t = 1;
	//cin >> t;
	while(t--)
	solve();
}