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fix: Fixed the state transition error in minCostClimbingStairsDP function (#839)

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Signed-off-by: foursevenlove <foursevenlove@gmail.com>
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47 2023-10-07 21:52:12 +08:00 committed by GitHub
parent 61e1d1faec
commit 70cff2d99f
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1 changed files with 14 additions and 4 deletions
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18
codes/go/chapter_dynamic_programming/min_cost_climbing_stairs_dp.go
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@ -4,14 +4,18 @@
package chapter_dynamic_programming package chapter_dynamic_programming
import "math"
/* 爬楼梯最小代价：动态规划 */ /* 爬楼梯最小代价：动态规划 */
func minCostClimbingStairsDP(cost []int) int { func minCostClimbingStairsDP(cost []int) int {
n := len(cost) - 1 n := len(cost) - 1
if n == 1 || n == 2 { if n == 1 || n == 2 {
return cost[n] return cost[n]
} }
min := func(a, b int) int {
if a < b {
return a
}
return b
}
// 初始化 dp 表，用于存储子问题的解 // 初始化 dp 表，用于存储子问题的解
dp := make([]int, n+1) dp := make([]int, n+1)
// 初始状态：预设最小子问题的解 // 初始状态：预设最小子问题的解
@ -19,7 +23,7 @@ func minCostClimbingStairsDP(cost []int) int {
dp[2] = cost[2] dp[2] = cost[2]
// 状态转移：从较小子问题逐步求解较大子问题 // 状态转移：从较小子问题逐步求解较大子问题
for i := 3; i <= n; i++ { for i := 3; i <= n; i++ {
dp[i] = int(math.Min(float64(dp[i-1]), float64(dp[i-2]+cost[i]))) dp[i] = min(dp[i-1], dp[i-2]) + cost[i]
} }
return dp[n] return dp[n]
} }
@ -30,12 +34,18 @@ func minCostClimbingStairsDPComp(cost []int) int {
if n == 1 || n == 2 { if n == 1 || n == 2 {
return cost[n] return cost[n]
} }
min := func(a, b int) int {
if a < b {
return a
}
return b
}
// 初始状态：预设最小子问题的解 // 初始状态：预设最小子问题的解
a, b := cost[1], cost[2] a, b := cost[1], cost[2]
// 状态转移：从较小子问题逐步求解较大子问题 // 状态转移：从较小子问题逐步求解较大子问题
for i := 3; i <= n; i++ { for i := 3; i <= n; i++ {
tmp := b tmp := b
b = int(math.Min(float64(a), float64(tmp+cost[i]))) b = min(a, tmp) + cost[i]
a = tmp a = tmp
} }
return b return b