java-MT46 外卖满减
import java.util.Arrays;
import java.util.Scanner;
public class Main {
public static void main(String[] args){
Scanner in = new Scanner(System.in);
while(in.hasNext()){
solution1(in);
solution2(in);
solution3(in);
solution4(in);
}
}
/**
* 动态规划: 01背包(一维)
* dp[j]表示不超过j元的最高消费
* 达到x元(>=x)选择价格总和最低的菜品组合 -> 不超过sum-x(<=sum-x)选择价格总和最高的菜品组合
* @param in
*/
private static void solution4(Scanner in){
int n = in.nextInt();
int x = in.nextInt();
int[] prices = new int[n+1];
int sum = 0;
for(int i=1; i<=n; i++){
prices[i] = in.nextInt();
sum += prices[i];
}
int v = sum-x;
int[] dp = new int[v+1];
for(int i=1; i<=n; i++){
for(int j=v; j>=prices[i]; j--){
dp[j] = Math.max(dp[j], dp[j-prices[i]]+prices[i]);
}
}
System.out.println(sum-dp[v]);
}
/**
* 动态规划: 01背包(二维)
* dp[i][j]表示有i种菜品时不超过j元的最高消费
* 达到x元(>=x)选择价格总和最低的菜品组合 -> 不超过sum-x(<=sum-x)选择价格总和最高的菜品组合
* @param in
*/
private static void solution3(Scanner in){
int n = in.nextInt();
int x = in.nextInt();
int[] prices = new int[n+1];
int sum = 0;
for(int i=1; i<=n; i++){
prices[i] = in.nextInt();
sum += prices[i];
}
int v = sum-x;
int[][] dp = new int[n+1][v+1];
for(int i=1; i<=n; i++){
// for(int j=0; j<=v; j++){
for(int j=v; j>=0; j--){
dp[i][j] = dp[i-1][j];
if(j >= prices[i]){
dp[i][j] = Math.max(dp[i][j], dp[i-1][j-prices[i]]+prices[i]);
}
}
}
System.out.println(sum-dp[n][v]);
}
/**
* 动态规划: 01背包(一维)[背包变体]
* dp[j]表示达到j元的最低消费
* @param in
*/
private static void solution2(Scanner in){
int n = in.nextInt();
int x = in.nextInt();
int[] prices = new int[n+1];
for(int i=1; i<=n; i++){
prices[i] = in.nextInt();
}
int[] dp = new int[x+1];
Arrays.fill(dp, 10001);
for(int i=1; i<=n; i++){
for(int j=x; j>=0; j--){
if(j > prices[i]){
dp[j] = Math.min(dp[j], dp[j-prices[i]]+prices[i]);
}else{
dp[j] = Math.min(dp[j], prices[i]);
}
}
}
System.out.println(dp[x]);
}
/**
* 动态规划: 01背包(二维)[背包变体]
* dp[i][j]表示有i种菜品时达到j元的最低消费
* @param in
*/
private static void solution1(Scanner in){
int n = in.nextInt();
int x = in.nextInt();
int[] prices = new int[n+1];
for(int i=1; i<=n; i++){
prices[i] = in.nextInt();
}
int[][] dp = new int[n+1][x+1];
for(int i=0; i<=n; i++){
Arrays.fill(dp[i], 10001);
}
for(int i=1; i<=n; i++){
// for(int j=0; j<=x; j++){
for(int j=x; j>=0; j--){
if(j > prices[i]){
dp[i][j] = Math.min(dp[i-1][j], dp[i-1][j-prices[i]]+prices[i]);
}else{
dp[i][j] = Math.min(dp[i-1][j], prices[i]);
}
}
}
System.out.println(dp[n][x]);
}
}