<p>There is a strange printer with the following two special properties:</p>

<ul>
	<li>The printer can only print a sequence of <strong>the same character</strong> each time.</li>
	<li>At each turn, the printer can print new characters starting from and ending at any place and will cover the original existing characters.</li>
</ul>

<p>Given a string <code>s</code>, return <em>the minimum number of turns the printer needed to print it</em>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> s = &quot;aaabbb&quot;
<strong>Output:</strong> 2
<strong>Explanation:</strong> Print &quot;aaa&quot; first and then print &quot;bbb&quot;.
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> s = &quot;aba&quot;
<strong>Output:</strong> 2
<strong>Explanation:</strong> Print &quot;aaa&quot; first and then print &quot;b&quot; from the second place of the string, which will cover the existing character &#39;a&#39;.
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= s.length &lt;= 100</code></li>
	<li><code>s</code> consists of lowercase English letters.</li>
</ul>

class Solution {
    string remdupl(string s){
        string ans;
        char prev = 'A';
        for(auto x: s){
            if(x != prev){
                ans.push_back(x);
                prev = x;
            }
        }
        return ans;
    }
    int dp[101][101];
    int rec(int l, int r, string s){
        if(l > r) return 0;
        if(l == r) return 1;
        if(dp[l][r] == -1){
            char start = s[l];
            int ans = 1 + rec(l+1, r, s);
            for(int mid = l+1; mid <= r; mid++){
                if(s[mid] == start){
                    ans = min(ans, rec(l, mid-1, s) + rec(mid+1, r, s));
                }
            }
            dp[l][r] = ans;
        }
        return dp[l][r];
    }
public:
    int strangePrinter(string s) {
        s = remdupl(s);
        // cout << s << endl;
        int n = s.size();
        memset(dp, -1, sizeof(dp));

        return rec(0, n-1, s);
    }
};
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