HDU 2859 Phalanx

最新推荐文章于 2020-02-14 00:02:53 发布

原创最新推荐文章于 2020-02-14 00:02:53 发布 · 664 阅读

0 ·

CC 4.0 BY-SA版权

http://acm.hdu.edu.cn/showproblem.php?pid=2859

二维dp: dp[i][j] = min(dp[i-1][j+1]+1, cnt); ans = max(ans, dp[i][j])

#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
const int maxn = 1010;
const int inf = 0x3f3f3f3f;
int dp[maxn][maxn];
char str[maxn][maxn];
int n, ans;

int main()
{
    //freopen("aa.in", "r", stdin);
    //freopen("bb.out", "w", stdout);
    while(scanf("%d", &n) && n)
    {
        for(int i = 0; i < n; ++i)
        {
            scanf("%s", str[i]);
        }
        ans = 1;
        for(int i = 0; i < n; ++i)
        {
            dp[0][i] = 1;
        }
        for(int i = 1; i < n; ++i)
        {
            for(int j = 0; j < n; ++j)
            {
                int cnt = 0;
                while(str[i-cnt][j] == str[i][j+cnt])
                {
                    cnt++;
                    if(i - cnt < 0 || j + cnt >= n)
                        break;
                }
                if(cnt - 1 >= dp[i-1][j+1])
                    dp[i][j] = dp[i-1][j+1] + 1;
                else
                    dp[i][j] = cnt;
                ans = max(ans, dp[i][j]);
            }
        }
        printf("%d\n", ans);
    }
    return 0;
}