HDU 4804 Campus Design

HDU 4804

思路：

轮廓线dp

#include<bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define pi acos(-1.0)
#define LL long long
//#define mp make_pair
#define pb push_back
#define ls rt<<1, l, m
#define rs rt<<1|1, m+1, r
#define ULL unsigned LL
#define pll pair<LL, LL>
#define pii pair<int, int>
#define mem(a, b) memset(a, b, sizeof(a))
#define fio ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define fopen freopen("in.txt", "r", stdin);freopen("out.txt", "w", stout);
//head

const int N = 12;
const int MOD = 1e9 + 7;
int dp[2][1<<N][25];
int n, m, cur;
char mp[105][N];
void update(int a, int b, int t) {
    if(b & (1<<m)) dp[cur][b^(1<<m)][t] += dp[1-cur][a][t-1], dp[cur][b^(1<<m)][t] %= MOD;
}
void Update(int a, int b, int t) {
    if(b & (1<<m)) dp[cur][b^(1<<m)][t] += dp[1-cur][a][t], dp[cur][b^(1<<m)][t] %= MOD;
}
int main() {
    int c, d;
    while(~scanf("%d%d%d%d", &n, &m, &c, &d)) {
        for (int i = 0; i < n; i++) scanf("%s", mp[i]);
        cur = 0;
        mem(dp, 0);
        dp[cur][(1<<m)-1][0] = 1;
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < m; j++) {
                cur ^= 1;
                mem(dp[cur], 0);
                if(mp[i][j] == '1') {
                    for(int k = 0; k < (1<<m); k++) {
                        for (int l = 0; l <= d; l++) {
                            Update(k, (k<<1), l);
                            if(l)update(k, (k<<1)^1, l);
                            if(i && !(k & (1<<m-1))) Update(k, (k<<1)^(1<<m)^1, l);
                            if(j && !(k & 1)) Update(k, (k<<1)^3, l);
                        }
                    }
                }
                else {
                    for (int k = 0; k < (1<<m); k++) {
                        for (int l = 0; l <= d; l++) {
                            Update(k, (k<<1)^1, l);
                        }
                    }
                }
            }
        }
        LL ans = 0;
        for (int i = c; i <= d; i++) ans += dp[cur][(1<<m)-1][i], ans %= MOD;
        printf("%lld
", ans);
    }
    return 0;
}