● 完全背包
主要是看清01背包和完全背包的区别
//01背包
for(int i = 0;i<weight.size();i++){
for(int j = bagWeight;j>=weight[i];j--){
dp[j] = Math.max(dp[j],dp[j-weight[i]]+value[i]);
}
}
//完全背包
for(int i = 0;i<weight.size();i++){
for(int j =weight[i];j<=bagweight;j++)
{
dp[j] = max(dp[j],dp[j-weight[i]]+value[i]);
}
}
● 518. 零钱兑换 II
//完全背包经典题目
class Solution {
public int change(int amount, int[] coins) {
int[] dp = new int[amount+1];
dp[0] = 1;
for(int i = 0;i<coins.length;i++){
for(int j =coins[i];j<=amount;j++){
dp[j] += dp[j-coins[i]];//可以不断重复
}
}
return dp[amount];
}
}
● 377. 组合总和 Ⅳ
class Solution {
public int combinationSum4(int[] nums, int target) {
int[] dp = new int[target+1];
dp[0] = 1;
for(int i = 0;i<=target;i++){
for(int j = 0;j<nums.length;j++){
if(i>=nums[j]){
dp[i] += dp[i-nums[j]];
}
}
}
return dp[target];
}
}