mirror of
https://github.com/krahets/hello-algo.git
synced 2024-12-26 12:56:32 +08:00
89679a4a13
* feat(kotlin): add kotlin code for dynamic programming. * Update knapsack.kt * feat(kotlin): add kotlin codes for graph. * style(kotlin): reformatted the codes. * feat(kotlin): add kotlin codes for the chapter of greedy. * Update max_product_cutting.kt
53 lines
No EOL
1.6 KiB
Kotlin
53 lines
No EOL
1.6 KiB
Kotlin
/**
|
|
* File: coin_change_greedy.kt
|
|
* Created Time: 2024-01-25
|
|
* Author: curtishd (1023632660@qq.com)
|
|
*/
|
|
|
|
package chapter_greedy
|
|
|
|
/* 零钱兑换：贪心 */
|
|
fun coinChangeGreedy(coins: IntArray, amt: Int): Int {
|
|
// 假设 coins 列表有序
|
|
var am = amt
|
|
var i = coins.size - 1
|
|
var count = 0
|
|
// 循环进行贪心选择，直到无剩余金额
|
|
while (am > 0) {
|
|
// 找到小于且最接近剩余金额的硬币
|
|
while (i > 0 && coins[i] > am) {
|
|
i--
|
|
}
|
|
// 选择 coins[i]
|
|
am -= coins[i]
|
|
count++
|
|
}
|
|
// 若未找到可行方案，则返回 -1
|
|
return if (am == 0) count else -1
|
|
}
|
|
|
|
/* Driver Code */
|
|
fun main() {
|
|
// 贪心：能够保证找到全局最优解
|
|
var coins = intArrayOf(1, 5, 10, 20, 50, 100)
|
|
var amt = 186
|
|
var res = coinChangeGreedy(coins, amt)
|
|
println("\ncoins = ${coins.contentToString()}, amt = $amt")
|
|
println("凑到 $amt 所需的最少硬币数量为 $res")
|
|
|
|
// 贪心：无法保证找到全局最优解
|
|
coins = intArrayOf(1, 20, 50)
|
|
amt = 60
|
|
res = coinChangeGreedy(coins, amt)
|
|
println("\ncoins = ${coins.contentToString()}, amt = $amt")
|
|
println("凑到 $amt 所需的最少硬币数量为 $res")
|
|
println("实际上需要的最少数量为 3 ，即 20 + 20 + 20")
|
|
|
|
// 贪心：无法保证找到全局最优解
|
|
coins = intArrayOf(1, 49, 50)
|
|
amt = 98
|
|
res = coinChangeGreedy(coins, amt)
|
|
println("\ncoins = ${coins.contentToString()}, amt = $amt")
|
|
println("凑到 $amt 所需的最少硬币数量为 $res")
|
|
println("实际上需要的最少数量为 2 ，即 49 + 49")
|
|
} |