题解 | #二叉树遍历#

#include <stdio.h>
#include <string.h>

void getPostOrder(char* preOrder, char* inOrder, int len) {
    if (len <= 0) {
        return;
    }
    char root = *preOrder;//将前序遍历序列的第一个字符赋值给变量root
    int rootIndex = 0;
    while (inOrder[rootIndex] != root) {
        rootIndex++;
    }

    getPostOrder(preOrder + 1, inOrder, rootIndex);
    getPostOrder(preOrder + rootIndex + 1, inOrder + rootIndex + 1,
                 len - rootIndex - 1);

    printf("%c", root);
}

int main() {
    char preOrder[27], inOrder[27];
    while (scanf("%s", preOrder) != EOF) {
        scanf("%s", inOrder);
        int len = strlen(preOrder);
        getPostOrder(preOrder, inOrder, len);
        printf("\n");
    }

    return 0;
}