单源最短路模板
一:SPFA
#define INF 1000000000
#define MAXN 50010 //点个数
#define MAXM 6000000 //边条数
int dis[MAXN];//结果
struct Node{
int v, next;
int c;
}E[MAXM];
int head[MAXN];
int NE;
void init(int n)
{
for (int i = 0; i <= n; i ++)
{
head[i] = -1;
dis[i] = INF;
}
NE = 0;
}
void insert(int x, int y, int c)
{
E[NE].v = y;
E[NE].c = c;
E[NE].next = head[x];
head[x] = NE ++;
}
bool spfa(int s, int n)//s为起点
{
int p,i;
queue<int>q;
while(!q.empty())
q.pop();
bool hash[MAXN];
int count[MAXN];
memset (count, 0, sizeof(int) * (n + 2));
memset(hash,0,sizeof(bool) * ( n + 2)) ;
hash[s] = 1;
dis[s] = 0;
q.push(s);
count [s] = 1;
while(!q.empty())
{
p = q.front();
q.pop();
if(count[p] > n)
return false; //负环
hash[p] = 0;
for(i = head[p]; i != -1; i = E[i].next)
{
int v = E[i].v;
int cc = E[i].c;
if(dis[p] + cc < dis[v] || dis[v] == INF)
//v - u <= k时候是这样的,如果v - u >= k 改符号
{
dis[v] = dis[p] + cc;
if(hash[v] == 0)
{
count[v] ++;
hash[v] = 1;
q.push(v);
}
}
}
}
return 1;
}
二:dijstra
const int N = 1001; //点
using namespace std;
struct node
{
int l,dir;
}w;//边
struct In
{
int idx;
int l;
bool friend operator<(const In &a, const In &b)
{
return a.l > b.l;
}
}ww,zz;//bfs
vector<node>mmap[N];
priority_queue<In>q;
int dis[N];
int start, end; //start 起点, end 终点
int nodenum;//点数 = end
int n, m;
int base;
void init()
{
while (!q.empty())
q.pop();
int i;
for (i = 0; i <= nodenum; i++)
{
dis[i] = -1;
mmap[i].clear();
}
return;
}
inline void creat(int s, int e, int value)
{
w.l = value;
w.dir = e;
mmap[s].push_back(w);
return;
}
void dij()
{
int i, j;
ww.idx = start;
ww.l = 0;
int size = 0;
node now;
q.push(ww);
while (!q.empty())
{
ww = q.top();
q.pop();
if (dis[ww.idx] != -1)
continue;
dis[ww.idx] = ww.l;
if(ww.idx == end)
return; www.zzzyk.com
size = mmap[ww.idx].size();
for (i = 0;i < size; i++)
{
now = mmap[ww.idx][i];
zz.idx = now.dir;
zz.l = ww.l + now.l;
if(dis[zz.idx] == -1)
{
q.push(zz);
}
}
}
return;
}
补充:综合编程 , 其他综合 ,