题解 | Kevin的矩阵

import java.util.*;

public class Main{
    static Scanner in = new Scanner(System.in);
    static int work(int m, int k, int n, int[] a){
        int minn = 0x3f3f3f3f;
        for(int i=0;i<m;i++){
            int cnt = 0;
            for(int j=i;j<n;j+=m){
                if(a[j]!=k) cnt++;
            }
            minn = Math.min(minn, cnt);
        }
        return minn;
    }
    static void solve(){
        int n = in.nextInt();
        int m = in.nextInt();
        int k = in.nextInt();
        int[] a = new int[n+5];
        int ans = 0x3f3f3f3f;
        for(int i=0;i<n;i++) a[i] = in.nextInt();
        for(int i=m;i<=n && i-m < ans;i++){
            ans = Math.min(ans, work(i,k,n,a)+i-m);
        }
        for(int i=m-1;i>=1 && m-i < ans;i--){
            ans = Math.min(ans, work(i,k,n,a)+m-i);
        }
        System.out.println(ans);
    }
    public static void main(String[] args){
        int T;
        T = in.nextInt();
        while(T-- > 0) solve();
        return;
    }
}