LintCode:背包问题

LintCode:背包问题

动态规划，同样的算法，Python超时，JAVA通过，真是搞不明白，难道Python的效率真的如此之低吗。。。

Python

class Solution:
    # @param m: An integer m denotes the size of a backpack
    # @param A: Given n items with size A[i]
    # @return: The maximum size
    def backPack(self, m, A):
        # write your code here
        n = len(A)
        ans = [[0 for i in range(m+1)] for i in range(2)]
        for i in range(1, n):
            for j in range(1, m+1):
                if A[i] > j:
                    ans[1][j] = ans[0][j]
                else:
                    ans[1][j] = max(A[i]+ans[0][j-A[i]], ans[0][j])
            ans[0] = ans[1]
            ans[1] = [0 for i in range(m+1)]
        return ans[0][m]

Java

public class Solution {
    /**
     * @param m: An integer m denotes the size of a backpack
     * @param A: Given n items with size A[i]
     * @return: The maximum size
     */
    public int backPack(int m, int[] A) {
        int dp[][] = new int[2][m+1];
        for(int i=0; i<A.length; i++){
            for(int j=1; j<m+1; j++){
                if(A[i] > j){
                    dp[1][j] = dp[0][j];
                }
                else{
                    dp[1][j] = Math.max(dp[0][j-A[i]] + A[i], dp[0][j]);
                }
            }
            dp[0] = dp[1];
            dp[1] = new int[m+1];
        }
        return dp[0][m];
    }
}