Describe an efficient greedy algorithm for making change for a specified value using a minimum number of coins, assuming there are four denominations of coins (called quarters, dimes, nickels, and...

value using a minimum number of coins, assuming there are four denominations

of coins (called quarters, dimes, nickels, and pennies), with values

25, 10, 5, and 1, respectively. Argue why your algorithm is correct.

Give an example set of denominations of coins so that a greedy changemaking

algorithm will not use the minimum number of coins.