HDU 4090 GemAnd Prince

dfs.消寶石，每次可以把同色並且相連的寶石消掉，所謂相連，該格子周圍的8個格子都算是相連。消完之後，要下落，並且把空的列向右移，也就是說，保證前幾列不空，後邊都空。

每次找到一羣可消除的寶石（相連且大於3個），消掉，移動，記錄當前值及最大值，深搜，還原。

找的過程bfs，dfs都行吧，搜的同時就把相應的寶石消掉並記錄個數。如果剩下的最大值加當前值不大於已得到的最優值，就可以剪掉了。

#pragma comment(linker, "/STACK:1024000000,1024000000")
#include<algorithm>
#include<iostream>
#include<cstring>
#include<cstdio>
#include<cmath>
///LOOP
#define REP(i, n) for(int i = 0; i < n; i++)
#define FF(i, a, b) for(int i = a; i < b; i++)
#define FFF(i, a, b) for(int i = a; i <= b; i++)
#define FD(i, a, b) for(int i = a - 1; i >= b; i--)
#define FDD(i, a, b) for(int i = a; i >= b; i--)
///INPUT
#define RI(n) scanf("%d", &n)
#define RII(n, m) scanf("%d%d", &n, &m)
#define RIII(n, m, k) scanf("%d%d%d", &n, &m, &k)
#define RIV(n, m, k, p) scanf("%d%d%d%d", &n, &m, &k, &p)
#define RV(n, m, k, p, q) scanf("%d%d%d%d%d", &n, &m, &k, &p, &q)
#define RFI(n) scanf("%lf", &n)
#define RFII(n, m) scanf("%lf%lf", &n, &m)
#define RFIII(n, m, k) scanf("%lf%lf%lf", &n, &m, &k)
#define RFIV(n, m, k, p) scanf("%lf%lf%lf%lf", &n, &m, &k, &p)
#define RS(s) scanf("%s", s)
///OUTPUT
#define PN printf("\n")
#define PI(n) printf("%d\n", n)
#define PIS(n) printf("%d ", n)
#define PS(s) printf("%s\n", s)
#define PSS(s) printf("%s ", n)
#define PC(n) printf("CASE# %d:\n", n)
///OTHER
#define PB(x) push_back(x)
#define CLR(a, b) memset(a, b, sizeof(a))
#define CPY(a, b) memcpy(a, b, sizeof(b))
#define display(A, n, m) {REP(i, n){REP(j, m)PIS(A[i][j]);PN;}}
#define lson l, m, rt << 1
#define rson m + 1, r, rt << 1 | 1

using namespace std;
typedef long long LL;
typedef pair<int, int> P;
const int MOD = 1000000007;
const int INFI = 1e9 * 2;
const LL LINFI = 1e17;
const double eps = 1e-6;
const double pi = acos(-1.0);
const int N = 8;
const int M = 26;
const int move[8][2] = {0, 1,  0, -1,  1, 0,  -1, 0,  1, 1,  1, -1,  -1, 1,  -1, -1};

int map[N][N];
int n, m, k, cnt, ans;

int getsum()
{
    int s = 0;
    int sum[N];
    CLR(sum, 0);
    REP(i, n)REP(j, m)sum[map[i][j]]++;
    FFF(i, 1, k)if(sum[i] >= 3)s += sum[i] * sum[i];
    return s;
}

bool check(int x, int y)
{
    return x >= 0 && y >= 0 && x < n && y < m;
}

void dfs(int x, int y, int col, bool vis[][N])
{
    int tx, ty;
    REP(i, 8)
    {
        tx = x + move[i][0];
        ty = y + move[i][1];
        if(check(tx, ty) && !vis[tx][ty] && map[tx][ty] == col)
        {
            vis[tx][ty] = 1;
            map[tx][ty] = 0;
            cnt++;
            dfs(tx, ty, col, vis);
        }
    }
}

void movegem()
{
    REP(i, m)
    {
        int k = n - 1;
        FD(j, n, 0)if(map[j][i])map[k--][i] = map[j][i];
        while(k >= 0)map[k--][i] = 0;
    }
    int k = 0;
    REP(i, m)if(map[n - 1][i])
    {
        if(i != k)REP(j, n)map[j][k] = map[j][i], map[j][i] = 0;
        k++;
    }
}

void solve(int now)
{
    if(getsum() + now <= ans)return;
    bool vis[N][N];
    int tmp[N][N], t;
    CLR(vis, 0);
    REP(i, n)REP(j, m)
    {
        if(!map[i][j])vis[i][j] = 1;
        if(vis[i][j])continue;
        cnt = 0;
        REP(ii, n)REP(jj, m)tmp[ii][jj] = map[ii][jj];
        dfs(i, j, map[i][j], vis);
        if(cnt < 3)
        {
            REP(ii, n)REP(jj, m)map[ii][jj] = tmp[ii][jj];
            continue;
        }
        movegem();
        t = now + cnt * cnt;
        ans = max(ans, t);
        solve(t);
        REP(ii, n)REP(jj, m)map[ii][jj] = tmp[ii][jj];
    }
}

int main()
{
    //freopen("input.txt", "r", stdin);
    //freopen("output.txt", "w", stdout);

    while(RIII(n, m, k) != EOF)
    {
        REP(i, n)REP(j, m)RI(map[i][j]);
        ans = 0;
        solve(0);
        PI(ans);
    }
    return 0;
}