CTRL+A, CTRL+C, CTRL+V

標籤：

(http://leetcode.com/2011/01/ctrla-ctrlc-ctrlv.html)

Imagine you have a special keyboard with the following keys:

A

Ctrl + A

Ctrl + C

Ctrl + V

where CTRL+A, CTRL+C, CTRL+V each acts as one function key for "Select All", "Copy", and "Paste" operations respectively.

If you can only press the keyboard for N times (with the above four keys), please write a program to produce maximum numbers of A. If possible, please also print out the sequence of keys.

That is to say, the input parameter is N (No. of keys that you can press), the output is M (No. of As that you can produce).

The Code:

int findMaxK(int n){    int power = 2;    double max = 0.0;    int maxK = 0;    while (n > 0)    {        n -= 2;        double t = (double)n/power;        double r = pow(t, (double)power);        if (r > max)        {            maxK = power;            max = r;        }        power++;    }    return maxK;}unsigned int f(int n){    if (n <= 7)        return n;    int k = findMaxK(n);    int sum = n - 2*(k-1);    unsigned int mul = 1;    while (k > 0)    {        int avg = sum/k;        mul *= avg;        k--;        sum -= avg;    }    assert(sum == 0);    return mul;}

 

CTRL+A, CTRL+C, CTRL+V