UVa 129 困难的串

https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=65

题意:输出不包含两个相邻的重复子串。

思路：这就跟八皇后问题是一样的，注意判断子串是否相同就可以了。

#include<iostream>
using namespace std;

int n, l;
int str[100];
int flag;
int cnt;

void dfs(int cur)
{
    if (cnt++ == n)
    {
        for (int i = 0; i < cur; i++)
        {
            if (i % 64 == 0 && i) cout << endl;
            else if (i % 4 == 0 && i)    cout << " ";
            char c = 'A' + str[i];
            cout << c;
        }
        flag = 1;
        cout << endl;
        cout << cur << endl;
        return;
    }
    else
    {
        for (int i = 0; i < l; i++)
        {
            str[cur] = i;
            int ok = 1;
            for (int j = 1; 2 * j <= cur + 1; j++)
            {
                int equal = 1;
                for (int k = 0; k < j; k++)
                {
                    if (str[cur - k] != str[cur - k - j])
                    {
                        equal = 0;
                        break;
                    }
                }
                if (equal)
                {
                    ok = 0;
                    break;
                }
            }
            if (ok)  if(!flag) dfs(cur + 1);
        }
    }
}

int main()
{
    while (cin >> n >> l && n)
    {
        flag = 0;
        cnt = 0;
        dfs(0);
    }
    return 0;
}