【LG3237】[HNOI2014]米特运输

题面

洛谷

题解

代码

#include <iostream> 
#include <cstdio> 
#include <cstdlib> 
#include <cstring> 
#include <cmath> 
#include <algorithm> 
using namespace std;
inline int gi() {
    register int data = 0, w = 1;
    register char ch = 0;
    while (!isdigit(ch) && ch != '-') ch = getchar(); 
    if (ch == '-') w = -1, ch = getchar();
    while (isdigit(ch)) data = 10 * data + ch - '0', ch = getchar();
    return w * data; 
} 
const double eps = 1e-8;
const int MAX_N = 5e5 + 5; 
struct Graph { int to, next; } e[MAX_N << 1];
int fir[MAX_N], e_cnt;
void clearGraph() { memset(fir, -1, sizeof(fir)); } 
void Add_Edge(int u, int v) { e[e_cnt] = (Graph){v, fir[u]}, fir[u] = e_cnt++; } 
int N, a[MAX_N], deg[MAX_N]; 
double f[MAX_N];

void dfs(int x, double s) {
    f[x] = s + log(a[x]);
    for (int i = fir[x]; ~i; i = e[i].next) dfs(e[i].to, s + log(deg[x]));
}

int main() {
#ifndef ONLINE_JUDGE
	freopen("cpp.in", "r", stdin); 
#endif
	clearGraph(); 
    N = gi(); 
    for (int i = 1; i <= N; i++) a[i] = gi(); 
    for (int i = 1, u, v; i < N; i++) u = gi(), v = gi(), ++deg[u], Add_Edge(u, v); 
    dfs(1, 0);
    sort(&f[1], &f[N + 1]); 
    int ans = 1; 
    for (int i = 2, cnt = 1; i <= N; i++) { 
        if (f[i] - f[i - 1] <= eps) ans = max(ans, ++cnt); 
        else cnt = 1; 
    } 
    printf("%d
", N - ans); 
    return 0;
}