寒假练习 1016 滑雪

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#define maxn 106
#define inf 9999999
#define up i-1,j,map[i][j]
#define down i+1,j,map[i][j]
#define left i,j-1,map[i][j]
#define right i,j+1,map[i][j]
//动态转移方程：
//dp[i][j] = 1+max(dp[i-1][j],dp[i+1][j],dp[i][j-1],dp[i][j+1])
int map[maxn][maxn];
int dp[maxn][maxn];
void init()
{
memset(map,-1,sizeof(map));
memset(dp,-1,sizeof(dp));
}
int maxmap(int a1,int a2,int a3,int a4) //求4各值中的最大值
{
if(a1 < a2) a1 = a2;
if(a1 < a3) a1 = a3;
if(a1 < a4) a1 = a4;
return a1;
}
int dpsum(int i,int j,int h)
{
//排除边界或者非递增情况
if(map[i][j]==-1 || h <= map[i][j])  return 0;

if(dp[i][j] >= 0) return dp[i][j];//这个点以前已经求过

dp[i][j] = maxmap(dpsum(up),dpsum(down),dpsum(left),dpsum(right))+1;

return dp[i][j];
}
int main()
{
int R,C;

while(~scanf("%d%d",&R,&C))
{
init();

for(int i = 1;i<=R;i++)
for(int j = 1;j<=C;j++)
scanf("%d",&map[i][j]);

int maxans = 0;

for(int i=1;i<=R;i++)
{
for(int j=1;j<=C;j++)
{
int len = dpsum(i,j,map[i][j]+1);
if(maxans < len) maxans = len;
}
}

printf("%d\n",maxans);
}

return 0;
}