[UVa] 10161 - Ant on a Chess Board

#include <cstdio>
#include <iostream>
#include <cmath>
using namespace std;
typedef long long ll;

ll sum(ll n)
{
    return n*n;
}

int main()
{
    ll i, lev, lim, mid;

    while (cin >> i && i)
    {
        lev = (ll)ceil(sqrt(i));
        if (lev&1)
        {
            lim = lev*lev;
            mid = lim - (lev-1);
            if (i<mid)
            {
                cout << lev << " " << i-(lev-1)*(lev-1) << endl;
            } else
            {
                cout << lim-(i)+1 << " " << lev << endl;
            }
        } else
        {
            lim = lev*lev;
            mid = lim - (lev-1);
            if (i>=mid)
            {
                cout << lev << " " << lim-i+1 << endl;
            } else
            {
                cout << i-(lev-1)*(lev-1) << " " << lev << endl;
            }
        }
    }
    return 0;
}

[UVa] 11000 - Bee

This is all about careful reading and a very bit of analysis.
First analyze what happens with a Male bee. You'll see every year the number of bees in that tree is a Fibonacci number, since all the past bees are dead by then.
Then for a Female be, it's actually the same, because it gives birth to a Male bee the next year. And since the special bee produces one Male bee each year, so the result is actually the sum of Fibonacci numbers till n.

#include <iostream>
#include <cmath>
using namespace std;
long long sum[100], fibs[100];
int fib( ) {
    int i;
    long long lim = (long long)pow(2.00,32);

    fibs[0]=0LL; sum[0]=0LL;
    fibs[1]=1LL; sum[1]=1LL;
    fibs[2]=1LL; sum[2]=2LL;
    for (i=3 ; sum[i-1]<lim ; i++) {
        fibs[i]=fibs[i-1]+fibs[i-2];
        sum[i]=sum[i-1]+fibs[i];
    }

    return i;
}

int main( ) {
    fib();
    int n;
    while (cin >> n && n>=0)
    {
        cout << sum[n] << " " << sum[n+1] << endl;
    }
    return 0;
}