Demonstrating usage of cache, with ArrayList, 2 dimensional array and basic loops

Question

So, it's one of our labs at Computers Systems Architecture, in which we are required to illustrate the process of cache(ArrayList of string) working with main memory(2 dimensional array of int) each [i][j] of that contains 4 int elements(cyan, magenta, yellow, black) of class Color. Therefore, we must show number of hits, misses, hit/miss-ratio and total accessed array cells.

I have mistake in my boolean cacheCheck() function, it never returns true! Was looking for error hours long, my will became weak, Help me! XD`

my function:

public static boolean cacheCheck(int i, int j, int color, ArrayList<String>     
cache){
boolean Check = false;

if(cache.size() >= 3) {
String firstElement = cache.get(cache.size()-3);
secondElement = cache.get(cache.size()-2);
String thirdElement = cache.get(cache.size()-1);
if(firstElement.equals(String.valueOf(i)) &&     
secondElement.equals(String.valueOf(j))){
if(thirdElement.equals(String.valueOf(mainMemory[i][j].c)) ||
thirdElement.equals(String.valueOf(mainMemory[i][j].m)) || 
thirdElement.equals(String.valueOf(mainMemory[i][j].y)) ||
thirdElement.equals(String.valueOf(mainMemory[i][j].k)))
                                Check = true;
}
}
return Check;
}

full java code

package cacheprocess;

import java.util.ArrayList;
import java.util.Scanner;


public class CacheProcess {

public static Color[][] mainMemory;
public static ArrayList<String> Cache = new ArrayList<>();


public static void main(String[] args) {


}

public static void init(){
int N,M,K;
float mRate, hRate;

Scanner s = new Scanner(System.in);
int algorithmNum;

do {
System.out.println("Enter N");
N = s.nextInt();
System.out.println("Enter M");
M = s.nextInt();
} while (!(((M*N)%2) == 0));

do {
System.out.println("Enter number of K blocks :");
K = s.nextInt();
} while (!((K%2) == 0) && K > (N * M / 4));
do {
System.out.println("Choose algorithm:");
algorithmNum = s.nextInt();  
int [] h;

switch(algorithmNum) {
case 1: 
h=Algorithm1(N,M,K);
break;
//case 2: 
//    h=Algorithm2(N,M,K);
//  break;
// case 3: 
//    h=Algorithm3(N,M,K);
// System.out.println("Y Total:  " + h[3]);
//   System.out.println("Y Miss:   " + h[4]);
//break;
default: 
h=Algorithm1(N,M,K);
break;
}
mRate=(float)h[1]/(float)h[0];
hRate=(float)h[2]/(float)h[0];
System.out.println("Total access: " + h[0]);
System.out.println("Miss:  " + h[1]);
System.out.println("Hit:   " + h[2]);
System.out.println("Miss Rate:   " + mRate);
System.out.println("Hit Rate:    " + hRate +"\n\n");
}while(true);                     
}


public static int [] Algorithm1(int N,int M, int K){

int[] result = new int[3];

mainMemory = new Color[N][M];

int miss = 0,  totalAccess = 0, cellsFilled = 0;

for (int i = 0; i < N; i++) {
for (int j = 0; j < M; j++) {
mainMemory[i][j] = new Color();
mainMemory[i][j].c = 0;
mainMemory[i][j].m = 0;
mainMemory[i][j].y = 1;
mainMemory[i][j].k = 0;
}
}


for (int i = 0; i < N; i++) {
for (int j = 0; j < M; j++) {


Cache.add( String.valueOf(i) + String.valueOf(j)+ mainMemory[i][j].c);
cellsFilled++;                                                        
if(cellsFilled == K){
Cache.clear();
}                                                        

if(!cacheCheck(i,j,mainMemory[i][j].y, Cache)){                            
miss++;
totalAccess++;
}


Cache.add(String.valueOf(i)+String.valueOf(j)+mainMemory[i][j].m);
cellsFilled++;
if(cellsFilled == K){
Cache.clear();
}

if(!cacheCheck(i,j,mainMemory[i][j].y, Cache)){                            
miss++;
totalAccess++;
}



Cache.add((String.valueOf(i)+String.valueOf(j)+mainMemory[i][j].y));
cellsFilled++;
if(cellsFilled == K){
Cache.clear();
}
if(!cacheCheck(i,j,mainMemory[i][j].y, Cache)){                            
miss++;
totalAccess++;
}


Cache.add((String.valueOf(i)+String.valueOf(j)+mainMemory[i][j].k));
cellsFilled++;
if(cellsFilled == K){
Cache.clear();
}

if(!cacheCheck(i,j,mainMemory[i][j].y, Cache)){                            
miss++;
totalAccess++;

}



}
}
result[0]=totalAccess;
result[1]=miss;
result[2]=totalAccess-miss;
return result;
}


public static boolean cacheCheck(int i, int j, int color, ArrayList<String>     
cache){
boolean Check = false;

if(cache.size() >= 3) {
String firstElement = cache.get(cache.size()-3);
secondElement = cache.get(cache.size()-2);
String thirdElement = cache.get(cache.size()-1);
if(firstElement.equals(String.valueOf(i)) &&     
secondElement.equals(String.valueOf(j))){
if(thirdElement.equals(String.valueOf(mainMemory[i][j].c)) ||
thirdElement.equals(String.valueOf(mainMemory[i][j].m)) || 
thirdElement.equals(String.valueOf(mainMemory[i][j].y)) ||
thirdElement.equals(String.valueOf(mainMemory[i][j].k)))
                                Check = true;
}
}
return Check;
}