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fix(csharp): fix csharp method name in knapsack (#592)

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* fix(csharp): fix csharp method name in knapsack

* feat(csharp): add csharp code for min path sum

* move INF define into method

* change INF to int max value
This commit is contained in:
hpstory
2023-07-10 17:34:54 +08:00
committed by GitHub
parent 459449d41a
commit 5ea016816a
2 changed files with 138 additions and 14 deletions
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28
codes/csharp/chapter_dynamic_programming/knapsack.cs
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@ -8,24 +8,24 @@ namespace hello_algo.chapter_dynamic_programming;
public class knapsack {
/* 0-1 背包：暴力搜索 */
public int knapsack_dfs(int[] weight, int[] val, int i, int c) {
public int knapsackDFS(int[] weight, int[] val, int i, int c) {
// 若已选完所有物品或背包无容量，则返回价值 0
if (i == 0 || c == 0) {
return 0;
}
// 若超过背包容量，则只能不放入背包
if (weight[i - 1] > c) {
return knapsack_dfs(weight, val, i - 1, c);
return knapsackDFS(weight, val, i - 1, c);
}
// 计算不放入和放入物品 i 的最大价值
int no = knapsack_dfs(weight, val, i - 1, c);
int yes = knapsack_dfs(weight, val, i - 1, c - weight[i - 1]) + val[i - 1];
int no = knapsackDFS(weight, val, i - 1, c);
int yes = knapsackDFS(weight, val, i - 1, c - weight[i - 1]) + val[i - 1];
// 返回两种方案中价值更大的那一个
return Math.Max(no, yes);
}
/* 0-1 背包：记忆化搜索 */
public int knapsack_dfs_mem(int[] weight, int[] val, int[][] mem, int i, int c) {
public int knapsackDFSMem(int[] weight, int[] val, int[][] mem, int i, int c) {
// 若已选完所有物品或背包无容量，则返回价值 0
if (i == 0 || c == 0) {
return 0;
@ -36,18 +36,18 @@ public class knapsack {
}
// 若超过背包容量，则只能不放入背包
if (weight[i - 1] > c) {
return knapsack_dfs_mem(weight, val, mem, i - 1, c);
return knapsackDFSMem(weight, val, mem, i - 1, c);
}
// 计算不放入和放入物品 i 的最大价值
int no = knapsack_dfs_mem(weight, val, mem, i - 1, c);
int yes = knapsack_dfs_mem(weight, val, mem, i - 1, c - weight[i - 1]) + val[i - 1];
int no = knapsackDFSMem(weight, val, mem, i - 1, c);
int yes = knapsackDFSMem(weight, val, mem, i - 1, c - weight[i - 1]) + val[i - 1];
// 记录并返回两种方案中价值更大的那一个
mem[i][c] = Math.Max(no, yes);
return mem[i][c];
}
/* 0-1 背包：动态规划 */
public int knapsack_dp(int[] weight, int[] val, int cap) {
public int knapsackDP(int[] weight, int[] val, int cap) {
int n = weight.Length;
// 初始化 dp 表
int[,] dp = new int[n + 1, cap + 1];
@ -67,7 +67,7 @@ public class knapsack {
}
/* 0-1 背包：状态压缩后的动态规划 */
public int knapsack_dp_comp(int[] weight, int[] val, int cap) {
public int knapsackDPComp(int[] weight, int[] val, int cap) {
int n = weight.Length;
// 初始化 dp 表
int[] dp = new int[cap + 1];
@ -95,7 +95,7 @@ public class knapsack {
int n = weight.Length;
// 暴力搜索
Console.WriteLine(knapsack_dfs(weight, val, n, cap));
Console.WriteLine(knapsackDFS(weight, val, n, cap));
// 记忆化搜索
int[][] mem = new int[n + 1][];
@ -104,12 +104,12 @@ public class knapsack {
Array.Fill(mem[i], -1);
}
Console.WriteLine(knapsack_dfs_mem(weight, val, mem, n, cap));
Console.WriteLine(knapsackDFSMem(weight, val, mem, n, cap));
// 动态规划
Console.WriteLine(knapsack_dp(weight, val, cap));
Console.WriteLine(knapsackDP(weight, val, cap));
// 状态压缩后的动态规划
Console.WriteLine(knapsack_dp_comp(weight, val, cap));
Console.WriteLine(knapsackDPComp(weight, val, cap));
}
}