秋招刷题4（动态规划）

1.购物单

import java.util.Scanner;

public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int m = sc.nextInt();

        Goods[] goods = new Goods[m];
        for(int i = 0; i < m; i++){
            goods[i] = new Goods();
        }
        for(int i = 0; i < m; i++){
            int v = sc.nextInt();
            int p = sc.nextInt();
            int q = sc.nextInt();
            goods[i].v = v;
            goods[i].p = p * v;  // 直接用p*v，方便后面计算
            if(q==0){
                goods[i].main = true;
            }else if(goods[q-1].a1 == -1){
                goods[q-1].a1 = i;
            }else{
                goods[q-1].a2 = i;
            }
        }

        int[][] dp = new int[m+1][N+1];
        for(int i = 1; i <= m; i++){
            for(int j = 0; j <= N; j++){
                dp[i][j] = dp[i-1][j];
                if(!goods[i-1].main){
                    continue;
                }
                if(j>=goods[i-1].v){
                    dp[i][j] = Math.max(dp[i][j], dp[i-1][j-goods[i-1].v] + goods[i-1].p);
                }
                if(goods[i-1].a1 != -1 && j >= goods[i-1].v + goods[goods[i-1].a1].v){
                    dp[i][j] = Math.max(dp[i][j], dp[i-1][j-goods[i-1].v - goods[goods[i-1].a1].v] + goods[i-1].p + goods[goods[i-1].a1].p);
                }
                if(goods[i-1].a2 != -1 && j >= goods[i-1].v + goods[goods[i-1].a2].v){
                    dp[i][j] = Math.max(dp[i][j], dp[i-1][j-goods[i-1].v - goods[goods[i-1].a2].v] + goods[i-1].p + goods[goods[i-1].a2].p);
                }
                if(goods[i-1].a1 != -1 && goods[i-1].a2 != -1 &&  j >= goods[i-1].v + goods[goods[i-1].a1].v + goods[goods[i-1].a2].v){
                    dp[i][j] = Math.max(dp[i][j], dp[i-1][j-goods[i-1].v - goods[goods[i-1].a1].v - goods[goods[i-1].a2].v] + goods[i-1].p + goods[goods[i-1].a1].p + goods[goods[i-1].a2].p);
                }
            }
        }
        System.out.println(dp[m][N]);
    }
}

class Goods {
    int v;
    int p;
    boolean main = false;

    int a1 = -1;  //定义附件1的编号
    int a2 = -1;  //定义附件2的编号
}

LCR.088使用最小花费爬楼梯

class Solution {
    public int minCostClimbingStairs(int[] cost) {
        int n=cost.length;
        int[] dp=new int[n+1];
        dp[0]=dp[1]=0;
        for(int i=2;i<=n;i++){
            dp[i]=Math.min(dp[i-1]+cost[i-1],dp[i-2]+cost[i-2]);
        }
        return dp[n];
    }
}

LCR98.不同路径

class Solution {
    public int uniquePaths(int m, int n) {
        int[][] dp=new int[m][n];
        dp[0][0]=1;
        for(int j=1;j<n;j++){
            dp[0][j]=1;
        }
        for(int i=1;i<m;i++){
            dp[i][0]=1;
        }
        for(int i=1;i<m;i++){
            for(int j=1;j<n;j++){
                dp[i][j]=dp[i-1][j]+dp[i][j-1];
            }
        }
        return dp[m-1][n-1];
    }
}

2.坐标移动

这个正则真的秒

import java.util.*;

import java.io.*;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) throws IOException{
        BufferedReader bf=new BufferedReader(new InputStreamReader(System.in));
        String[] in=bf.readLine().split(";");
        int x=0;
        int y=0;
        for(String s:in){
            if(!s.matches("[WASD][0-9]{1,2}")){
               continue; 
            }
            int val=Integer.valueOf(s.substring(1));
            switch(s.charAt(0)){
                case 'W':
                   y+=val;
                   break;
                case 'S':
                    y-=val;
                    break;
                case 'A':
                    x-=val;
                    break;
                case 'D':
                    x+=val;
                    break;
            }
        }
        System.out.println(x+","+y);
        }
}