UVa 699 Falling Leaves

#include<stdio.h>#define HASHSIZE 20000typedef struct TreeNode{    int val;    int pos;    struct TreeNode* left;    struct TreeNode* right;}Node;int arr[HASHSIZE];int hashmap[HASHSIZE];int ans[HASHSIZE];void preorder(Node* rt){    if(rt == NULL) return;    printf("%d ", rt->pos);    preorder(rt->left);    preorder(rt->right);}Node* buildtree(int* cur, int p){    if(arr[*cur] == -1)    {        (*cur)++;        return NULL;    }    Node* newnode = (Node*)malloc(sizeof(Node));    newnode->val = arr[*cur];    newnode->pos = p;    hashmap[newnode->pos] += newnode->val;    (*cur)++;    newnode->left = buildtree(cur, p-1);    newnode->right = buildtree(cur, p+1);    return newnode;}void ReadInput(){    int i, leaf, nonleaf;    int num = 1;    while(1)    {        i = 0, leaf = 0, nonleaf = 0;        memset(ans, 0, sizeof(ans));        memset(hashmap, 0, sizeof(hashmap));        do        {            scanf("%d", &arr[i]);            if(arr[i] == -1) leaf++;            else nonleaf++;            i++;        }while((nonleaf+1) != leaf);        if(leaf == 1) break;        int c = 0;        Node* root = buildtree(&c, HASHSIZE/2);        int j = 0, k = 0;        for(j = 0; j < HASHSIZE; j++)            if(hashmap[j]) ans[k++] = hashmap[j];        printf("Case %d:\n", num++);        for(j = 0; j < k; j++)        {            if(j != k - 1)                printf("%d ", ans[j]);            else                printf("%d", ans[j]);        }        printf("\n\n");    }}int main(){    ReadInput();    return 0;}