Uva10285 Longest Run on a Snowboard

记忆化搜索模板题.

仔细想想搜索时会重复的地方, 然后把重复的地方记下来就好啦!

#include <cstdio>
#include <algorithm>
#include <iostream>
#include <cstring>
using namespace std;
const int MAXC = 100 + 10;
const int INF = 0x3f3f3f3f;

inline int read()
{
    int x = 0; char ch = getchar();
    while(!isdigit(ch)) ch = getchar();
    while(isdigit(ch)) x = x * 10 + ch - '0', ch = getchar();
    return x;
}

int M[MAXC][MAXC], d[MAXC][MAXC], dx[4] = {-1, 0, 1, 0}, dy[4] = {0, 1, 0, -1}; 
int R, C;

int dfs(int x, int y)
{
    if(d[x][y] != -1) return d[x][y];

    d[x][y] = 0;
    for(int i = 0; i < 4; i++)
        if(M[x + dx[i]][y + dy[i]] < M[x][y])
            d[x][y] = max(dfs(x + dx[i], y + dy[i]), d[x][y]);

    return ++d[x][y];
}

int main()
{
    //freopen("10285.in", "r", stdin);
    int N;
    cin>>N;

    string s;

    while(N--)
    {
        cin>>s;
        R = read(), C = read();

        memset(M, 0, sizeof(M));
        memset(d, -1, sizeof(d));
        for(int i = 1; i <= R; i++)
            for(int j = 1; j <= C; j++)
                M[i][j] = read();

        for(int i = 1; i <= R; i++)
            {for(int j = 1; j <= C; j++)
                cout<<M[i][j]<<" ";
            cout<<endl;}

        int ans = -INF;
        for(int i = 1; i <= R; i++)
            for(int j = 1; j <= C; j++)
                ans = max(dfs(i, j), ans);

        cout<<s<<": "<<--ans<<endl;
    }
    return 0;
}

做水题真好玩!