48 lines
940 B
C#
Executable File
48 lines
940 B
C#
Executable File
// knapsack problem
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public class Solution
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{
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public int NumberOfWays(int n, int x)
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{
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const int MOD = 1_000_000_007;
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// list all the powers which smaller than n
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var powers = new List<int>();
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var num = 1;
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while (true)
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{
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int pow = (int)Math.Pow(num, x);
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if (pow > n)
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break;
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powers.Add(pow);
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num++;
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}
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// dynamic programming
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var dp = new int[n + 1];
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dp[0] = 1;
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foreach (var power in powers)
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{
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for (var i = n; i >= power; i--)
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{
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dp[i] = (dp[i] + dp[i - power]) % MOD;
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}
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}
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return dp[n];
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}
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}
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class Program
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{
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static void Main()
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{
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var solution = new Solution();
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Console.WriteLine(solution.NumberOfWays(4, 1));
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Console.WriteLine(solution.NumberOfWays(100, 3));
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}
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} |