二叉树遍历

根据前序遍历和中序遍历写出后序遍历

#include<iostream>#include<cstdio>#include<cstring>#include<algorithm>using namespace std;char in_order[30],pre_order[30];int num[30],co[30];int cmp(int a,int b){return (num[a]<num[b]);}int main(){//freopen("data.txt","r",stdin);while(scanf("%s%s",pre_order,in_order)!=EOF){int len=strlen(in_order);memset(num,len,sizeof(num));for(int i=0;i<len;i++){int j;for(j=0;j<len;j++)if(in_order[j]==pre_order[i])break;int tot=0;for(int k=len-1;k>=0;k--){if(k==j) continue;if(k>j&&num[k]==num[j]){tot++;num[k]--;}if(k<j&&num[k]==num[j])num[k]=num[k]-tot-1;}co[i]=i;}sort(co,co+len,cmp);for(int i=0;i<len;i++)printf("%c",in_order[co[i]]);printf("\n");}return 0;}