二维数组dp

#include<iostream>
#include<vector>
using namespace std;vector<int>weight = { 1,3,4 };
vector<int>value = { 15,20,30 };
int bagWeight = 4;
vector<vector<int>>dp(weight.size() + 5, vector<int>(bagWeight + 5, 0));
//dp[i][j]表示从0-i个物品中选取最大容量为j的背包所容纳的最大价值void printDp(vector<vector<int>>& dp)
{for (int i = 0; i < weight.size(); i++){for (int j = 0; j <= bagWeight; j++){cout << dp[i][j] << " ";}cout << endl;}
}
int main()
{int i, j;//初始化for (j = weight[0]; j <= bagWeight; j++){dp[0][j] = value[0];}cout << "开始dp前" << endl;printDp(dp);//开始dpfor (i = 1; i < weight.size(); i++){for (j = 0; j <= bagWeight; j++){if (j < weight[i]){dp[i][j] = dp[i - 1][j];}else{dp[i][j] = max(dp[i - 1][j], dp[i][j - weight[i]] + value[i]);}}}cout << "完成dp后" << endl;printDp(dp);cout << "最大价值为：" << dp[weight.size() - 1][bagWeight] << endl;return 0;
}

一维数组

#include<iostream>
#include<vector>
using namespace std;vector<int>weight = { 1,3,4 };
vector<int>value = { 15,20,30 };
int bagWeight = 4;
vector<int>dp(bagWeight+5, 0);
//dp[j]表示背包最大容量为j的所放物品的最大价值void printDp(vector<int>& dp)
{for (int j = 0; j <= bagWeight; j++){cout << dp[j] << " ";}
}
int main()
{int i, j;//开始dpfor (i = 0; i < weight.size(); i++){for (j = bagWeight; j >= weight[i]; j--){dp[j] = max(dp[j], dp[j - weight[i]] + value[i]);}printDp(dp);cout << endl;}cout << "最大价值为：" << dp[bagWeight] << endl;return 0;
}