poj 2100 Graveyard Design

#include <iostream>#include <cstdio>#include <cstring>#include <algorithm>using namespace std;typedef long long ll;typedef pair<ll,ll> pii;#define maxn 1000000ll n;pii ans[maxn];int main(){    while(~scanf("%I64d",&n)) { ll s = 1,pos = 1,sum = 0; int len = 0; for(;s * s <= n; ++s) {         while(sum < n) {      sum += pos * pos;      ++pos;         }         if(sum == n) {      ans[len].first = pos - s;      ans[len++].second = s;         }         sum -= s * s; } printf("%dn",len); for(int i = 0; i < len; ++i) {         printf("%I64d",ans[i].first);         for(int j = 0; j < ans[i].first; ++j)      printf(" %I64d",ans[i].second + j);         printf("n"); }    }    return 0;}