蔡子经数据结构5.11

#include <string.h>
#include <stdlib.h>

typedef struct 
{
    int ltag;
    char data;
    int rtag;
} node;
#define MAXN 8
node a[MAXN] =
{
    {0,'A',0},
    {1,'B',0},
    {0,'D',1},
    {1,'F',1},
    {0,'C',1},
    {0,'E',1},
    {1,'G',0},
    {1,'H',1}
};

int idx = 0;
int findPar(int par, char aim)
{
    int cur = idx;
    idx++;
    if(a[cur].data == aim) return par;
    int ret = -1;
    if(a[cur].ltag == 0)
        ret = findPar(cur, aim);
    if(ret != -1) return ret;
    if(a[cur].rtag == 0)
        ret = findPar(cur, aim);
    return ret;
}


int main()
{
    int res = findPar(-1, 'D');
    if(res == -1) puts("not found");
    else printf("%cn",a[res].data);
    return 0;
}