poj 1776 Task Sequences

#include<cstdio>#include<iostream>using namespace std;#include<cstring>#define MAXN 1000bool map[MAXN][MAXN];int next[MAXN];int head;int n;char line[2500];int main(){    int i,j,k;    while(scanf("%d",&n) != EOF)    {        getchar();        for(i = 0;i < n; i++)        { gets(line); int ct; for(j = 0,ct = 0;j < 2*n-1;j += 2) {     map[i][ct++] = line[j] -'0'; } next[i] = -1;        }        head = 0;        for(i = 1;i <n; i++)        { if(map[i][head]) {     next[i] = head;     head = i;     continue; } j = head; k = next[j]; while(k != -1) {     if(map[j][i] && map[i][k])     break;     j = k;     k = next[j]; } next[i] = k; next[j] = i;        }        printf("1n%dn",n);        for(i = 0; i < n;i++)        { if(i > 0)printf(" "); printf("%d",head+1); head = next[head];        }        printf("n");    }    return 0;}