Each year, fall in the North Central region is accompanied by the brilliant colors of the leaves on the trees, followed quickly by the falling leaves accumulating under the trees. If the same thing happened to binary trees, how large would the piles of leaves become?
We assume each node in a binary tree drops a number of leaves equal to the integer value stored in that node. We also assume that these leaves drop vertically to the ground (thankfully, there's no wind to blow them around). Finally, we assume that the nodes are positioned horizontally in such a manner that the left and right children of a node are exactly one unit to the left and one unit to the right, respectively, of their parent. Consider the following tree:
The nodes containing 5 and 6 have the same horizontal position (with different vertical positions, of course). The node containing 7 is one unit to the left of those containing 5 and 6, and the node containing 3 is one unit to their right. When the leaves drop from these nodes, three piles are created: the leftmost one contains 7 leaves (from the leftmost node), the next contains 11 (from the nodes containing 5 and 6), and the rightmost pile contains 3. (While it is true that only leaf nodes in a tree would logically have leaves, we ignore that in this problem.)
5 7 -1 6 -1 -1 3 -1 -1 8 2 9 -1 -1 6 5 -1 -1 12 -1 -1 3 7 -1 -1 -1 -1
Case 1: 7 11 3 Case 2: 9 7 21 15
題目大意:每個葉子在垂直方向落葉,最後垂直和是多少。
解題思路:將樹存在一個水平一維數組中(以數組中間為根節點,向兩邊建樹),就可以將統一豎線上的節點相加。
#include#include int tree[100], L, R; void build(int num, int pos) { int x, y; if (num != -1) { if (pos < L) L = pos; if (pos > R) R = pos; tree[pos] += num; scanf(%d, &x); build(x, pos - 1); scanf(%d, &y); build(y, pos + 1); } } int main() { int i, n, sum = 0; while (scanf(%d, &n) && n != -1) { memset(tree, 0, sizeof(tree)); sum++; L = 50; R = 50; build(n, 50); printf(Case %d: , sum); for (i = L ;i < R; i++) printf(%d , tree[i]); printf(%d , tree[R]); } return 0; }