HDU1505 City Game 动态规划

http://acm.hdu.edu.cn/showproblem.php?pid=1505

自己写的屌丝代码：

#include <cstdlib>
#include <cstring>
#include <cstdio>
#define MAXN 1050
using namespace std;

int N, M, u[MAXN][MAXN], l[MAXN][MAXN], G[MAXN][MAXN];

inline int max(int x, int y)
{
    return x > y ? x : y;
}

inline int min(int x, int y)
{
    return x < y ? x : y;
}

int DP()
{
    int Max = 0;
    for (int i = 1; i <= N; ++i) {
        for (int j = 1; j <= M; ++j) {
            if (G[i][j]) {
                int L = 1, H = 1, bx, by;
                by = u[i][j] = u[i-1][j] + 1;
                bx = l[i][j] = l[i][j-1] + 1;
                Max = max(Max, max(bx*H, by*L)); 
                for (int f = i-1; f > 0; --f) { 
                    
                    if (G[f][j]) {
                        ++H;
                        bx = min(bx, l[f][j]);
                    }
                    else {
                        break;
                    }
                    Max = max(Max, max(bx*H, by*L)); 
                } 
                for (int g = j-1; g > 0; --g) { 
                    
                    if (G[i][g]) {
                        ++L;
                        by = min(by, u[i][g]);
                    }
                    else {
                        break;
                    }
                    Max = max(Max, max(bx*H, by*L));
                }
            }
            else {
                u[i][j] = 0;
                l[i][j] = 0;
            }
        }
    }
    return Max;
}

int main()
{
    int T;
    char logo[4];
    scanf("%d", &T);
    while (T--) {
        scanf("%d %d", &N, &M);
        for (int i = 1; i <= N; ++i) {
            for (int j = 1; j <= M; ++j) {
               scanf("%s", logo);
               G[i][j] = (logo[0]== 'F');
            }
        }
        printf("%d\n", 3 * DP());
    }   
    return 0;
}

用1506的写法

#include<stdio.h>
#include<string.h>
#define M 1005
int a[M][M], l[M], r[M];

int main() {
    int t, i, j, res, ans, n, m;
    char str[10];
    scanf("%d", &t);
    while (t-- && scanf("%d %d", &n, &m)) {
        memset(a[0], 0, sizeof (a[0]));
        for (i = 1; i <= n; i++)
            for (j = 1; j <= m; j++) {
                scanf("%s", str);
                if (str[0] == 'F')a[i][j] = a[i - 1][j] + 1;
                else a[i][j] = 0;
            }
        ans = -1;
        for (i = 1; i <= n; i++) {
            for (j = 1; j <= m; j++)l[j] = r[j] = j;
            a[i][0] = a[i][m + 1] = -1;
            for (j = 2; j <= m; j++) {
                while (a[i][j] <= a[i][l[j] - 1])
                    l[j] = l[l[j] - 1];
            }
            for (j = m - 1; j >= 1; j--) {
                while (a[i][j] <= a[i][r[j] + 1])
                    r[j] = r[r[j] + 1];
            }
            for (j = 1; j <= m; j++) {
                res = a[i][j]*(r[j] - l[j] + 1);
                if (res > ans)ans = res;
            }
        }
        printf("%d\n", ans * 3);
    }
    return 0;
}