BZOJ 3040 最短路(road) 堆优化Dijkstra

标签：bzoj   dijkstra   heap+dijkstra   堆优化   最短路   

题目大意：最短路。

思路：最短路。

贴一份比较高效的堆优化Dij模板吧。

CODE：

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#define _MAX 1000010
#define MAX 10000010
using namespace std;
#define min(a,b) 	((a) < (b) ? a:b)

long long f[_MAX];

struct Heap{
	int num[_MAX],pos[_MAX],size;
	
	void PushUp(int p) {
		while(p > 1) {
			if(f[num[p]] < f[num[p >> 1]]) {
				swap(num[p],num[p >> 1]);
				swap(pos[num[p]],pos[num[p >> 1]]);
				p >>= 1;
			}
			else	break;
		}
	}
	void Insert(long long x) {
		num[++size] = x;
		pos[x] = size;
		PushUp(size);
	}
	void Pop() {
		pos[num[1]] = 0;
		num[1] = num[size--];
		if(size)	pos[num[1]] = 1;
		int now = 2;
		while(now < size) {
			if(f[num[now + 1]] < f[num[now]])
				++now;
			if(f[num[now]] < f[num[now >> 1]]) {
				swap(num[now],num[now >> 1]);
				swap(pos[num[now]],pos[num[now >> 1]]);
				now <<= 1;
			}
			else	break;
		}
	}
}heap;

int points,edges;
long long T,rxa,rxc,rya,ryc,rp;
int head[_MAX],total;
int next[MAX],aim[MAX],length[MAX];

inline void Add(int x,int y,int len)
{
	next[++total] = head[x];
	aim[total] = y;
	length[total] = len;
	head[x] = total;
}

void Dijkstra()
{
	memset(f,0x3f,sizeof(f));
	f[1] = 0;
	for(int i = 1; i <= points; ++i)
		heap.Insert(i);
	while(heap.size) {
		int x = heap.num[1]; heap.Pop();
		for(int i = head[x]; i; i = next[i])
			if(f[aim[i]] > f[x] + length[i])
				f[aim[i]] = f[x] + length[i],heap.PushUp(heap.pos[aim[i]]);
	}
}

int main()
{
	cin >> points >> edges;
	cin >> T >> rxa >> rxc >> rya >> ryc >> rp;
	int x = 0,y = 0,z = 0;
	int a,b;
	for(int i = 1; i <= T; ++i) {
		x = ((long long)x * rxa + rxc) % rp;
		y = ((long long)y * rxa + rxc) % rp;
		a = min(x % points + 1,y % points + 1);
		b = y % points + 1;
		if(a != b)	Add(a,b,1e8 - 100 * a);
	}
	for(int i = T + 1; i <= edges; ++i) {
		scanf("%d%d%d",&x,&y,&z);
		Add(x,y,z);
	}
	Dijkstra();
	cout << f[points] << endl;
	return 0;
}

BZOJ 3040 最短路(road) 堆优化Dijkstra

标签：bzoj   dijkstra   heap+dijkstra   堆优化   最短路   

原文地址：http://blog.csdn.net/jiangyuze831/article/details/41729905