Jumping | Blue Bridge Cup

jumping | Blue Bridge Cup

Topic link https://www.lanqiao.cn/problems/553/learning/

Topic analysis
The data structure of this problem is not big , May adopt dfs;
It's fine too dp;
The distance you can walk is only 9 individual , It is not allowed to walk two spaces below the syncline （ Although the distance is less than three ）, There seems to be some problems here

Code

dfs

#include<iostream>
#include<cmath>
#include<algorithm>
using namespace std;
int squ[101][101];
int book[101][101];
int dir[9][2] = {
     1,0,2,0,3,0,0,1,0,2,0,3,1,1,1,2,2,1 };
int m, n;
int maxx = -1;
void dfs(int x, int y,int sum)
{
    
	if (x == n && y == m)
	{
    
		if (sum > maxx)maxx = sum;
		return;
	}
	for (int k = 0; k < 9; k++)
	{
    
		int nx = x + dir[k][0];
		int ny = y + dir[k][1];
		if (nx >= 1 && ny >= 1 && nx <= n && ny <= m&&!book[nx][ny])
		{
    
			book[nx][ny] = 1;
			dfs(nx, ny, sum + squ[nx][ny]);
			book[nx][ny] = 0;
		}
	}
}
int main()
{
    
	cin >> n >> m;
	for (int i = 1; i <= n; i++)
		for (int j = 1; j <= m; j++)
			cin >> squ[i][j];
	book[1][1] = 1;
	dfs(1, 1, -4);
	cout << maxx;
	return 0;
}

dp

#include<iostream>
#include<cmath>
#include<algorithm>
using namespace std;
int squ[101][101];
int dp[101][101];
int dir[9][2] = {
     1,0,2,0,3,0,0,1,0,2,0,3,1,1,1,2,2,1 };
int main()
{
    
	int m, n;
	cin >> n >> m;
	for (int i = 1; i <= n; i++)
		for (int j = 1; j <= m; j++)
			cin >> squ[i][j];
	dp[1][1] = squ[1][1];
	for(int i=1;i<=n;i++)
		for(int j=1;j<=m;j++)
			for (int k = 0; k < 9; k++)
			{
    
				int nx = i + dir[k][0];
				int ny = j + dir[k][1];
				if (nx >= 1 && ny >= 1 && nx <= n && ny <= m)
					dp[nx][ny] = max(dp[nx][ny], dp[i][j] + squ[nx][ny]);
			}
	cout << dp[n][m];
	return 0;
}