leetcode 113 路径总和 II

题目

leetcode 113
给定一个二叉树和一个目标和，找到所有从根节点到叶子节点路径总和等于给定目标和的路径。
说明: 叶子节点是指没有子节点的节点。
示例:
给定如下二叉树，以及目标和 sum = 22，

代码

void dfs(struct TreeNode *root, int arr[], int ind, int **res, int *returnSize, int **returnColumnSizes, int sum) {
    if (root == NULL) return ;
    sum -= root->val;
    arr[ind++] = root->val;
    if (sum == 0 && root->left == NULL && root->right == NULL) {
        res[*returnSize] = (int *)malloc(sizeof(int) * ind);
        for (int i = 0; i < ind; i++) {
            res[*returnSize][i] = arr[i];
        }
        (*returnColumnSizes)[*returnSize] = ind;
        (*returnSize)++;
        return ;
    }
    dfs(root->left, arr, ind, res, returnSize, returnColumnSizes, sum);
    dfs(root->right, arr, ind, res, returnSize, returnColumnSizes, sum);
}
int** pathSum(struct TreeNode* root, int sum, int* returnSize, int** returnColumnSizes){
    *returnSize = 0;
    #define MAX 1000000
    int **res = (int **)malloc(sizeof(int *) * MAX);
    (*returnColumnSizes) = (int *)malloc(sizeof(int) * MAX);
    int arr[MAX];
    dfs(root, arr, 0, res, returnSize, returnColumnSizes, sum);
    return res;
}