LintCode "Backpack"

class Solution {
public:
    /**
    * @param m: An integer m denotes the size of a backpack
    * @param A: Given n items with size A[i]
    * @return: The maximum size
    */
    int backPack(int m, vector<int> A) {
        //  for i=1..N
        //      for v=V..0
        //          f[v]=max{f[v],f[v-c[i]]+w[i]}; 
        //
        size_t len = A.size();
        if (len == 0) return 0;

        int ret = 0;
        vector<bool> dp(m + 1, false);
        dp[0] = true;
        for (int i = 1; i <= len; i++)
        for (int v = m; v >= A[i - 1]; v--)
        {
            if (dp[v - A[i - 1]])
            {
                dp[v] = true;
                ret = max(ret, v);
            }
        }

        return ret;
    }
};