impar_keys.c

typedef struct node {
    int key;
    struct node *left;
    struct node *right;
} node;

int is_odd(node *n){
    // verify the root key
    if (n->key % 2 != 0)
        return 1;
    
    return 0;
}

int find_path_with_max_odd_keys(node *root){
    int keys, left_keys, right_keys = 0;
    
    if(is_odd(root) == 1)
        keys++;
    
    left_keys = find_path_with_max_odd_keys(root->left);
    right_keys = find_path_with_max_odd_keys(root->right);
    
    if(left_keys >= right_keys)
        return keys + left_keys;
    
    return keys + right_keys;
}