SDUTOJ 1489 求二叉树的先序遍历

<img src="http://img.blog.csdn.net/20141014212549703?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvUl9NaXNheWE=/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center" alt="" />

#include<stdio.h>#include<string.h>int cont;char st1[100],st2[100],ans[100];void build(int n,char *s1,char *s2,char *s){    if(n<=0) return;    int p=strchr(s1,s2[n-1])-s1;ans[cont++]=s2[n-1];    build(p,s1,s2,s);    build(n-p-1,s1+p+1,s2+p,s+p);}int main(){    int t;    scanf("%d",&t);    while(t--)    {        cont=0;        scanf("%s%s",st1,st2);        int len=strlen(st1);        build(len,st1,st2,ans);        ans[len]='\0';        printf("%s\n",ans);    }return 0;}