pku 1088 滑雪

#include <iostream>
using namespace std;
int map[100][100];
int v[100][100];
int m, n;
int Max = -1;
int x[] = {0, 0, 1, -1};
int y[] = {1, -1, 0, 0};
bool isOK(int i, int j)
{
if(i < 0 || j <0 || i >= m || j >= n)
return false;
return true;
}
int dfs(int i, int j)
{
if(v[i][j])
return v[i][j];
int max = 1;
for(int k = 0; k < 4; ++k)
{
int tempA = i+x[k];
int tempB = j+y[k];
if(isOK(tempA, tempB) && map[i][j] < map[tempA][tempB])
{
int temp = dfs(tempA, tempB);
if(1+temp > max)
max = 1+temp;
}
}
v[i][j] = max;
return v[i][j];
}
int main()
{
scanf("%d%d", &m, &n);
for(int i = 0; i < m; ++i)
for(int j = 0; j < n; ++j)
scanf("%d", &map[i][j]);
for(int i = 0; i < m; ++i)
for(int j = 0; j < n; ++j)
{
int ret = dfs(i, j);
if(ret > Max)
Max = ret;
}
printf("%d/n", Max);
return 0;
}
//经典记忆化搜索, 类似DP的记录方法.