求解数独

dfs爆搜，从第一个空开始试探

bool check(int sodu[10][10], int n, int m)
{
    int heng = n / 9;
    int zong = n % 9;
    int a = heng / 3, b = zong / 3;
    a *= 3, b *= 3;
    int i, j;
    for (i = 0; i < 9; i++)
        if (sodu[i][zong] == m)
            return false;
    for (i = 0; i < 9; i++)
        if (sodu[heng][i] == m)
            return false;
    for (i = a; i < a + 3; i++)
    {
        for (j = b; j < b + 3; j++)
        {
            if (sodu[i][j] == m)
                return false;
        }
    }
    return true;
}
void dfs(int sodu[10][10], int n, int &flag)
{
    if (n > 80)
    {
        flag = 1;
        return;
    }
    if (sodu[n / 9][n % 9] == 0)
    {
        for (int i = 1; i <= 9; i++)
        {
            if (check(sodu, n, i))
            {
                sodu[n / 9][n % 9] = i;
                dfs(sodu, n + 1, flag);
                if (!flag)
                    sodu[n / 9][n % 9] = 0;
                else
                    return;
            }
        }
    }
    else
        dfs(sodu, n + 1, flag);
}

原文地址：https://www.cnblogs.com/xiao-ma-running/p/8672012.html