vector<vector<string> > solveNQueens(int n)
{
// Start typing your C/C++ solution below
// DO NOT write int main() function
vector<int> queenPos(n, 0);
vector<int> curPosInLines(n,0);
int currentline = 0;
ret.clear();
if(n<=0) return ret;
while(currentline >=0)
{
bool validQ = isValidQueen(queenPos, n, currentline);
if(validQ)
{
if(currentline == n-1)
{
//ret++; // record a solution
vector<string> solution;
for(int i=0; i<n; i++)
{
string s(n, '.');
s[queenPos[i]] = 'Q';
solution.push_back(s);
}
ret.push_back(solution);
goNext(queenPos, currentline, n);
}
else
{
queenPos[++currentline] = 0;
}
}
else
{
goNext(queenPos, currentline, n);
}
}
return ret;
}
int totalNQueens(int n) {
int result = 0;
vector<int> queenPos(n, -1);
putQueen(queenPos, 0, n, result);
return result;
}
