使用 jGrasp 可视化递归

Question

the one that I like to see how it works graphically is this one

 public boolean splitArray(int[] nums) {
    int index = 0;
    int sum1 = 0;
    int sum2 = 0;

    return recallArray(nums, index, sum1, sum2);

}

public boolean recallArray(int[] nums, int index, int sum1, int sum2){
    if(index >= nums.length){
        return sum1 == sum2;
    }
        int value = nums[index];
        return recallArray(nums,index + 1, sum1 + value,sum2) 
        || recallArray(nums,index + 1, sum1 ,sum2 + value);
}

I try to use Jgrasp , that have a good visual debugger , but it only show me how the variables changes through the recursion calls, it is possible to Jgrasp to do the tree of recursion or something similar?, how?

Answer 1

You could do it yourself with a class (RACheck here) exploiting try-with-resources.

public boolean recallArray(int[] nums, int index, int sum1, int sum2) {
    try (new RACheck(nums, index, sum1, sum2)) {
        if (index >= nums.length) {
            return sum1 == sum2;
        }
        int value = nums[index];
        return recallArray(nums,index + 1, sum1 + value,sum2) 
            || recallArray(nums,index + 1, sum1 ,sum2 + value);
    }
}

class RACheck implements Autocloseable {
    static int recursionDepth;
    int myRecursionDepth;

    final int[] aliasToNums;
    final int[] copyOfNums;

    RAChec(int[] nums, int index, int sum1, int sum2) {
        myRecursionDepth = recursionDepth++;
        // copy initial values.
        this.aliasOfNums = nums;
        this.copyOfNums = Arrays.copyOf(nums, nums.length);
        // dump enter method
    }

    @Override
    public void close() {
        // dump leave method
        // highlight changes to nums
    }
}