链表专题

1、uva 11988 Broken Keyboard

　　题意：给出键盘打字的顺序，遇到[到句首，遇到]倒句末。求最后输出的句子。

　　思路：

①单向链表数组模拟

#include<iostream>
#include<cstring>
#include<cstdio>
using namespace std;
const int maxn = 100100;
char s[maxn];
int Next[maxn];
int main()
{
    while (~scanf("%s", s + 1))
    {
        int len = strlen(s + 1);
        Next[0] = 0;
        int cur = 0, last = 0;
        for (int i = 1; i <= len; i++)
        {
            if (s[i] == '[')cur=0 ;
            else if (s[i] == ']') cur = last;
            else
            {
                Next[i] = Next[cur];
                Next[cur] = i;
                if (last == cur) last = i;
                cur = i;
            }
        }
        for (int i = Next[0]; i != 0; i = Next[i]) printf("%c", s[i]);
        printf("
");
    }
    return 0;
}

②双向链表数组模拟

#include<iostream>
#include<cstring>
const int maxn = 100100;
char s[maxn];
int L[maxn], R[maxn];
int main()
{
    while (~scanf("%s", s+1))
    {
        int len = strlen(s+1);
        L[0] = R[0] = 0;
        for (int i = 1; i <= len; i++)
        {
            if (s[i] == '[') L[i] = 0, R[i] = R[0];
            else if (s[i] == ']') L[i] = L[0], R[i] = 0;
            else
            {
                L[i] = i - 1, R[i] = R[i - 1];
            }
            L[R[i]] = i, R[L[i]] = i;
        }
        for (int i = R[0]; i != 0; i = R[i])
        {
            if (s[i] == '[' || s[i] == ']')continue;
            printf("%c", s[i]);
        }
        printf("
");
    }
    return 0;
}

③STL list使用

#include<iostream>
#include<cstdio>
#include<cstring>
#include<list>
using namespace std;
const int maxn = 100100;
char s[maxn];

int main()
{
    while (~scanf("%s", s))
    {
        int len = strlen(s);
        list<char>lt;
        list<char>::iterator pos=lt.end();
        for (int i = 0; i < len; i++)
        {
            if (s[i] == '[') pos=lt.begin();
            else if (s[i] == ']') pos=lt.end();
            else
            {
                lt.insert(pos, s[i]);
            }
        }
        for (pos = lt.begin(); pos != lt.end(); pos++)
        {
            printf("%c", *pos);
        }
        printf("
");
    }
    return 0;
}