无需记忆化 卡过 880ms

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#define RG register
#define FT(i, A, B) for(RG int i = A;i <= B;i++)
using namespace std;
const int N = 105;
const int dx[]={-1, 0, 1, 0};
const int dy[]={ 0, 1, 0,-1};
int map[N][N], C, R;
int dist[N][N], ans;

inline void DFS(int x,int y){
    int vx, vy;
    if(dist[x][y] > ans) ans = dist[x][y];    
    FT(i,0,3){
        vx = x+dx[i];
        vy = y+dy[i];
        if(vx < 1 || vx > C || vy < 1 || vy > R) continue;
        if(map[vx][vy] > map[x][y])
            if(!dist[vx][vy] || dist[vx][vy] < dist[x][y] + 1)
                dist[vx][vy] = dist[x][y]+1, 
                DFS(vx,vy);
    }
}
int main(){
    scanf("%d%d", &C,&R);
    FT(i,1,C) FT(j,1,R)
        scanf("%d", &map[i][j]);
    FT(i,1,C) FT(j,1,R)    
        if(!dist[i][j])
            DFS(i,j);
    printf("%d\n", ans+1);
    return 0;
}

R.T