leetcode 52:N皇后 II

与leetcode 51基本一样

void solve(std::vector> &a,std::vector>b,std::vector s,int n,int len){
    if(len==n){
        a.push_back(s);
        return;
    }
    std::string str="";
    int flag=0;
    for(int i=0;i>c=b;
        if(b[len][i]==1)
            str+=".";
        else if(b[len][i]==0){
            str+="Q";
            flag=1;
            c[len][i]=1;
            for(int k=i;k=0;k++,l--){
                c[k][l]=1;
            }
            len++;
            for(int j=i+1;j> a;
    std::vector>b(n,std::vector(n));
    if(n==0)
        return 0;
    std::vector s;
    solve(a,b,s,n,0);
    return a.size();
}