硬币找零算法

public final class MakeChange  
{  
    // Dynamic programming algorithm to solve change making problem.  
    // As a result, the coinsUsed array is filled with the  
    // minimum number of coins needed for change from 0 -> maxChange  
    // and lastCoin contains one of the coins needed to make the change.  
    public static void makeChange( int [ ] coins, int differentCoins,  
                int maxChange, int [ ] coinsUsed, int [ ] lastCoin )  
    {  
        coinsUsed[ 0 ] = 0; lastCoin[ 0 ] = 1;  
 
        for( int cents = 1; cents <= maxChange; cents++ )  
        {  
            int minCoins = cents;  
            int newCoin  = 1;  
 
            for( int j = 0; j < differentCoins; j++ )  
            {  
                if( coins[ j ] > cents )   // Cannot use coin j  
                    continue;  
                if( coinsUsed[ cents - coins[ j ] ] + 1 < minCoins )  
                {  
                    minCoins = coinsUsed[ cents - coins[ j ] ] + 1;  
                    newCoin  = coins[ j ];  
                }  
            }  
 
            coinsUsed[ cents ] = minCoins;  
            lastCoin[ cents ]  = newCoin;  
        }  
    }