hoj1078

记忆化搜索，使用dfs，从0,0点开始，把每个点对应的剩下路程所能得到的最大值存入f数组。

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <vector>
#include <cmath>
#include <queue>
using namespace std;

#define maxn 105

int map[maxn][maxn];
int f[maxn][maxn];
int ans, fans, n, m;
int dir[4][2] =
{
{ 1, 0 },
{ 0, 1 },
{ -1, 0 },
{ 0, -1 } };

void input()
{
    for (int i = 0; i < n; i++)
        for (int j = 0; j < n; j++)
            scanf("%d", &map[i][j]);
}

bool ok(int x, int y)
{
    if (x < 0 || y < 0 || x >= n || y >= n)
        return false;
    return true;
}

int dfs(int x, int y)
{
    if (f[x][y] != -1)
        return f[x][y];
    int ans = 0;
    for (int i = 0; i < 4; i++)
        for (int j = 1; j <= m; j++)
        {
            if (!ok(x + dir[i][0] * j, y + dir[i][1] * j))
                break;
            if (map[x + dir[i][0] * j][y + dir[i][1] * j] > map[x][y])
            {
                int temp = dfs(x + dir[i][0] * j, y + dir[i][1] * j);
                if (temp > ans)
                    ans = temp;
            }
        }
    f[x][y] = map[x][y] + ans;
    return f[x][y];
}

int main()
{
    //freopen("D:\\t.txt", "r", stdin);
    while (scanf("%d%d", &n, &m) != EOF)
    {
        if (n == -1 && m == -1)
            break;
        input();
        memset(f, -1, sizeof(f));
        printf("%d\n", dfs(0, 0));
    }
    return 0;
}