原题染色没什么好说的

#include <cstring>
#include <iostream>
#include <algorithm>

using namespace std;

const int N = 310;

int n;
int c[N];
int f[N][N];

int main()
{
    cin >> n;

    for (int i = 1; i <= n; i ++ ) cin >> c[i];

    memset(f, 0x3f, sizeof f);
    for (int len = 1; len <= n; len ++ ) 
        for (int l = 1; l + len - 1 <= n; l ++ ) 
        {
            int r = l + len - 1;
            if (l == r) f[l][r] = 1;
            else if (c[l] == c[r]) f[l][r] = min(f[l][r - 1], f[l + 1][r]);
            else
                for (int k = l; k < r; k ++ )
                    f[l][r] = min(f[l][r], f[l][k] + f[k + 1][r]);
        }

    cout << f[1][n] << endl;

    return 0;
}