FirstFit.java

public class FirstFit {
    // Method to allocate memory to 
    // blocks as per First fit algorithm 

    static void firstFit(int blockSize[], int m, int processSize[], int n) {
        // Stores block id of the 
        // block allocated to a process 
        int allocation[] = new int[n];

        // Initially no block is assigned to any process 
        for (int i = 0; i < allocation.length; i++) {
            allocation[i] = -1;
        }

        // pick each process and find suitable blocks 
        // according to its size ad assign to it 
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < m; j++) {
                if (blockSize[j] >= processSize[i]) {
                    // allocate block j to p[i] process 
                    allocation[i] = j;

                    // Reduce available memory in this block. 
                    blockSize[j] -= processSize[i];

                    break;
                }
            }
        }

        System.out.println("\nProcess No.\tProcess Size\tBlock no.");
        for (int i = 0; i < n; i++) {
            System.out.print(" " + (i + 1) + "\t\t" + processSize[i] + "\t\t");
            if (allocation[i] != -1) {
                System.out.print(allocation[i] + 1);
            } else {
                System.out.print("Not Allocated");
            }
            System.out.println();
        }
    }

    // Driver Code 
    public static void main(String[] args) {
        int blockSize[] = {100, 500, 200, 300, 600};
        int processSize[] = {212, 417, 112, 426};
        int m = blockSize.length;
        int n = processSize.length;

        firstFit(blockSize, m, processSize, n);
    }
}