My C solution with Time Limit Exceeded

  • 0

    I kept getting Time Limited Exceeded with C code, not entirely sure why.

     * Definition for a binary tree node.
     * struct TreeNode {
     *     int val;
     *     struct TreeNode *left;
     *     struct TreeNode *right;
     * };
     * Return an array of size *returnSize.
     * Note: The returned array must be malloced, assume caller calls free().
    double* averageOfLevels(struct TreeNode* root, int* returnSize) {
        double *tree_avg = malloc(*returnSize * sizeof(double));
        int c=0;
        struct TreeNode *parent,*current;
        if(!tree_avg || !root)
            return 0;
        parent = NULL;
        current = root;
        while (current) {
            if ((current->left) && (current->right)) {
                tree_avg[c++] = (double)(((double)current->left->val + (double)current->right->val)/2);            
                parent = current;
                current = current->left;
            } else {
                if(parent) {
                    current = parent->right;
                    if (!(current->left) && !(current->right))
                    current= 0;
        return tree_avg;

  • 0

    I didn't have a chance to dig into it other than a quick glance. The first problem I noticed is you are allocating space for tree_avg using the value of *returnSize, which is zero to start with, and I didn't see a call to realloc() to resize the tree_avg later when you start using it. I'm surprised that's not giving you other issues.

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