Uva11988 Broken Keyboard

//Uva11988 Broken Keyboard#include<cstdio>#include<cstring>const int maxn = 100000+5;int cur, last, next[maxn];char s[maxn];int main(){    while(scanf("%s", s+1) == 1)    {        int len = strlen(s+1);        cur = last = 0;        next[0] = 0;        for(int i=1; i<=len; i++)        {            char ch = s[i];            if(ch == '[') cur = 0;            else if(ch == ']') cur = last;            else            {                next[i] = next[cur];                next[cur] = i;                if(cur == last) last = i;                cur = i;            }        }        for(int i=next[0]; i!=0; i=next[i])            printf("%c", s[i]);        printf("\n");    }    return 0;}