Solution.java

class Solution {
    public int strangePrinter(String s) {
        final int inf = 1 << 30;
        int n = s.length();
        int[][] f = new int[n][n];
        for (var g : f) {
            Arrays.fill(g, inf);
        }
        for (int i = n - 1; i >= 0; --i) {
            f[i][i] = 1;
            for (int j = i + 1; j < n; ++j) {
                if (s.charAt(i) == s.charAt(j)) {
                    f[i][j] = f[i][j - 1];
                } else {
                    for (int k = i; k < j; ++k) {
                        f[i][j] = Math.min(f[i][j], f[i][k] + f[k + 1][j]);
                    }
                }
            }
        }
        return f[0][n - 1];
    }
}