結果

問題 No.828 全方位神童数
コンテスト
ユーザー akakimidori
提出日時 2019-06-06 09:56:14
言語 C
(gcc 13.3.0)
結果
AC  
実行時間 88 ms / 2,000 ms
コード長 3,457 bytes
コンパイル時間 438 ms
コンパイル使用メモリ 32,128 KB
実行使用メモリ 7,808 KB
最終ジャッジ日時 2024-09-24 23:57:38
合計ジャッジ時間 6,221 ms
ジャッジサーバーID
（参考情報） 		judge1 / judge3
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ファイルパターン 結果
sample AC * 3
other AC * 43
権限があれば一括ダウンロードができます

ソースコード

diff # 

#include<stdio.h>
#include<stdlib.h>
#include<stdint.h>
#include<inttypes.h>
#include<string.h>

typedef int32_t i32;
typedef int64_t i64;

typedef struct directed_edge {
  int32_t vertex;
  int32_t next;
} graph_edge;

typedef struct directedGraph {
  graph_edge *edge;
  int32_t *start;
  int32_t pointer;
  int32_t vertex_num;
  int32_t edge_max_size;
} graph;

graph* new_graph (const int vertex_num) {
  graph *g = (graph *) calloc (1, sizeof (graph));
  g->edge = (graph_edge *) calloc (1, sizeof (graph_edge));
  g->start = (int32_t *) calloc (vertex_num, sizeof (int32_t));
  g->pointer = 0;
  g->vertex_num = vertex_num;
  g->edge_max_size = 1;
  for (int32_t i = 0; i < vertex_num; ++i) {
    g->start[i] = -1;
  }
  return g;
}

void add_edge (graph *g, int32_t from, int32_t to) {
  if (g->pointer == g->edge_max_size) {
    g->edge_max_size *= 2;
    g->edge = (graph_edge *) realloc (g->edge, sizeof (graph_edge) * g->edge_max_size);
  }
  g->edge[g->pointer] = (graph_edge) {to, g->start[from]};
  g->start[from] = g->pointer++;
}

typedef struct union_find {
  int32_t *parent;
  i32 *sum;
  int32_t size;
} union_find;

void init_union_find (union_find * const u) {
  for (int32_t i = 0; i < u->size; ++i){
    u->parent[i] = -1;
    u->sum[i] = 0;
  }
}

union_find* new_union_find (const int32_t size) {
  union_find * const u = (union_find *) calloc (1, sizeof (union_find));
  u->parent = (int32_t *) calloc (size, sizeof (int32_t));
  u->sum = (i32 *) calloc (size, sizeof (i32));
  u->size = size;
  init_union_find (u);
  return u;
}

int32_t root (union_find * const u, int32_t x) {
  i32 stack[32];
  i32 top = 0;
  stack[top++] = x;
  while (u->parent[x] >= 0) {
    x = u->parent[x];
    stack[top++] = x;
  }
  i32 r = stack[top - 1];
  i32 sum = 0;
  for (i32 i = top - 2; i >= 0; --i) {
    i32 y = stack[i];
    i32 next = sum + u->sum[y];
    u->sum[y] += sum;
    sum = next;
    u->parent[y] = r;
  }
  return r;
}

int same (union_find * const u, const int32_t x, const int32_t y) {
  return root (u, x) == root (u, y);
}

int32_t get_size (union_find * const u, const int32_t x) {
  return - (u->parent[root (u, x)]);
}

void unite (union_find * const u, int32_t x, int32_t y) {
  x = root (u, x);
  y = root (u, y);
  if (x == y) return;
  if (u->parent[x] > u->parent[y]) {
    const int32_t swap = x;
    x = y;
    y = swap;
  }
  u->parent[x] += u->parent[y];
  u->parent[y] = x;
  u->sum[y] -= u->sum[x];
}

void add (union_find *u, i32 x, i32 v) {
  u->sum[root (u, x)] += v;
}

i32 get_sum (union_find *u, i32 x) {
  i32 r = root (u, x);
  return r == x ? u->sum[x] : u->sum[x] + u->sum[r];
}

void run (void) {
  i32 n;
  scanf ("%" SCNi32, &n);
  i32 *r = (i32 *) calloc (n, sizeof (i32));
  for (i32 i = 0; i < n; ++i) {
    scanf ("%" SCNi32, r + i);
  }
  graph *g = new_graph (n);
  for (i32 i = 1; i < n; ++i) {
    i32 a, b;
    scanf ("%" SCNi32 "%" SCNi32, &a, &b);
    a--; b--;
    add_edge (g, a, b);
    add_edge (g, b, a);
  }
  union_find *u = new_union_find (n);
  for (i32 i = 0; i < n; ++i) {
    for (i32 p = g->start[i]; p != -1; p = g->edge[p].next) {
      i32 v = g->edge[p].vertex;
      if (v > i) continue;
      unite (u, i, v);
    }
    add (u, i, 1);
  }
  const i32 mod = 1000000007;
  i32 ans = 1;
  for (i32 i = 0; i < n; ++i) {
    i32 c = get_sum (u, i);
    ans = (i64) ans * (r[i] + c) % mod;
  }
  printf ("%" PRIi32 "\n", ans);
}

int main (void) {
  run();
  return 0;
}
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