hnoi2013

match和walk当场AC，所以不贴了～

seq:

#include <cstdio>
#ifdef WIN32
#define fmt64 "%I64d"
#else
#define fmt64 "%lld"
#endif
#define int64 long long

using namespace std;

int64 N, K, M, P;

int64 fpm (int64 a, int64 b)
{
	int64 res = 1;
	for (; b; b >>= 1, a = a * a % P)
		if (b & 1) res = res * a % P;
	return res;
}

int main ()
{
	freopen ("seq.in", "r", stdin);
	freopen ("seq.out", "w", stdout);

	scanf (fmt64 fmt64 fmt64 fmt64, &N, &K, &M, &P);
	N %= P;
	printf (fmt64"\n", (N * fpm(M, K - 1) % P - (M + 1) * M / 2 % P * (K - 1) % P * fpm(M, K - 2) % P + P) % P);
}

cake:

#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <cstring>
#include <ctime>
#include <algorithm>

#define uns unsigned
#define int64 long long
#ifdef WIN32
#define fmt64 "%I64d"
#else
#define fmt64 "%lld"
#endif
#define oo 0x13131313
#define REP(i, n) for (i = 0; i < (n); ++i)
#define maxn (40 * 40 * 40 + 5)
#define dual(e) (edges + (((e) - edges) ^ 1))

using namespace std;

struct edge { int t, f; edge *n; };

edge edges[maxn * 10], *adjc = edges, *adj[maxn];
int P, Q, R, D, tot, S, T, ans;
int p[45][45][45], v[45][45][45], q[maxn], dis[maxn];

void link (int u, int v, int f)
{
	if (u && v) {
		*adjc = (edge) {v, f, adj[u]}, adj[u] = adjc++;
		*adjc = (edge) {u, 0, adj[v]}, adj[v] = adjc++;
	}
}

bool bfs ()
{
	int h, t;
	memset (dis, 0, sizeof dis), dis[S] = 1;
	for (q[h = t = S] = -1; ~h; h = q[h])
		for (edge *e = adj[h]; e; e = e->n)
			if (e->f && !dis[e->t]) {
				dis[e->t] = dis[h] + 1;
				t = q[t] = e->t, q[t] = -1;
			}
	return dis[T];
}

int dfs (int u, int f)
{
	if (u == T) return f;
	int l = f;
	for (edge *e = adj[u]; e; e = e->n)
		if (e->f && dis[e->t] == dis[u] + 1) {
			int x = dfs (e->t, min(e->f, f));
			e->f -= x, dual (e)->f += x, f -= x;
			if (!f) return l;
		}
	return dis[u] = -1, l - f;
}

int main ()
{
	freopen ("cake.in", "r", stdin);
	freopen ("cake.out", "w", stdout);

	int i, j, k;
	scanf ("%d%d%d%d", &P, &Q, &R, &D);
	for (k = 1; k <= R; ++k)
		for (i = 1; i <= P; ++i)
			for (j = 1; j <= Q; ++j) {
				scanf ("%d", v[i][j] + k);
				p[i][j][k] = ++tot;
			}

	S = ++tot, T = ++tot;
	for (i = 1; i <= P; ++i)
		for (j = 1; j <= Q; ++j) {
			link (S, p[i][j][1], oo);
			p[i][j][R + 1] = T;
			for (k = 1; k <= R; ++k) {
				link (p[i][j][k], p[i][j][k + 1], v[i][j][k]);
				if (k > D) {
					link (p[i][j][k], p[i + 1][j][k - D], oo);
					link (p[i][j][k], p[i - 1][j][k - D], oo);
					link (p[i][j][k], p[i][j + 1][k - D], oo);
					link (p[i][j][k], p[i][j - 1][k - D], oo);
				}
			}
		}

	for (; bfs (); )
		ans += dfs (S, oo);
	printf ("%d\n", ans);
}