逆转广义表

题目

请编写递归算法, 逆转广义表中的数据元素。例如: 将广义表:
(a,((b,c),()),(((d),e),f))逆转为:((f,(e,(d))),((),(c,b)),a)

代码
#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;

void reverse_str(char *s, int l, int r)
{
    
    
    int n = r-l;
    for (int i = 0; i < n/2; ++i)
        swap(s[l+i], s[l+(n-1-i)]);
}

void reverse_list_recur(char *s, int l, int r)
{
    
    
    int i = l, last_i = l;
    int c1 = 0, c2 = 0;
    do {
    
    
        if (s[i] == '(') ++c1;
        else if (s[i] == ')') ++c2;
        if ((c1 == c2+1 && s[i] == ',') || (c1 == c2 && s[i] == ')')) {
    
    
            reverse_list_recur(s, last_i+1, i);
            reverse_str(s, last_i+1, i);
            last_i = i;
        }
        ++i;
    } while (c1 != c2);
    reverse_str(s, l+1, r-1);
}

int main()
{
    
    
    char s[] = "(a,((b,c),()),(((d),e),f))";
    reverse_list_recur(s, 0, strlen(s));
    cout << s << endl;
    system("pause");
    return 0;
}

猜你喜欢

转载自blog.csdn.net/w112348/article/details/112136548