1031. Hello World for U (20)

http://www.patest.cn/contests/pat-a-practise/1031

//8:44#include <iostream>#include <string>using namespace std;int n1,n2,n3;int N,maxk;void is(){for(int k = n2;k>=1;k--){if( (2*k+n2-2) == N ){if(maxk < k){maxk = k;}}}}int main(){string s;cin>>s;N = s.size();for(n2 = 3;n2 <= s.size();n2++){is();}n1 = n3 = maxk;n2 = N - n1 - n3 + 2;int i,k;for(i = 0,k=N-1;i < n1-1;i++,k--){cout<<s[i];for(int j = 0;j<n2-2;j++){cout<<" ";}cout<<s[k]<<endl;}for(;i < n1+n2-1;i++){cout<<s[i];}return 0;}