堆优化后的dijkstra算法模板(以hdu2544为例)

vector实现版,优点是代码量较少,缺点是常数较大。

#pragma comment(linker, "/STACK:102400000,102400000")
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
using namespace std;
#define pt(a) cout<=a;i--)
#define pii pair
#define fi first
#define se second
#define ll long long
#define ull unsigned long long
#define pb push_back
#define mp make_pair
#define inf 0x3f3f3f3f
#define eps 1e-10
#define PI acos(-1.0)
const ll mod = 1e9+7;
const int N = 1e3+10;

ll qp(ll a,ll b) {ll res=1;a%=mod; assert(b>=0); for(;b;b>>=1){if(b&1)res=res*a%mod;a=a*a%mod;}return res;}
int to[4][2]={{-1,0},{1,0},{0,-1},{0,1}};

int n,m,d[N];
struct eg{
    int to,len;
};
vector g[N];

void dij() {
    mst(d,inf);
    d[1]=0;
    priority_queue,greater > pq;
    pq.push({0,1});
    while(!pq.empty()) {
        pii tp=pq.top(); pq.pop();
        int u=tp.se;
        if(d[u]!=tp.fi) continue;///等价于vis标记
        for(int i=0;i>n>>m&&(n+m)) {
        for(int i=1;i<=n;i++) g[i].clear();
        for(int i=1;i<=m;i++) {
            int a,b,c;
            cin>>a>>b>>c;
            g[a].pb(eg{b,c});
            g[b].pb(eg{a,c});
        }
        dij();
    }
    return 0;
}

 

链式前向星实现边,优点是常数较小,缺点是代码量较大。

#pragma comment(linker, "/STACK:102400000,102400000")
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
using namespace std;
#define pt(a) cout<=a;i--)
#define pii pair
#define fi first
#define se second
#define ll long long
#define ull unsigned long long
#define pb push_back
#define mp make_pair
#define inf 0x3f3f3f3f
#define eps 1e-10
#define PI acos(-1.0)
const ll mod = 1e9+7;
const int N = 1e2+10;
const int M = 1e4+10;

ll qp(ll a,ll b) {ll res=1;a%=mod; assert(b>=0); for(;b;b>>=1){if(b&1)res=res*a%mod;a=a*a%mod;}return res;}
///int to[4][2]={{-1,0},{1,0},{0,-1},{0,1}};

int n,m,d[N],hd[N],tot;
int nt[M],to[M],w[M];

void init() {
    tot=0;
    mst(hd,-1);
}

void add(int u,int v,int val) {
    to[tot]=v;
    w[tot]=val;
    nt[tot]=hd[u];
    hd[u]=tot++;
}

void dij() {
    mst(d,inf);
    d[1]=0;
    priority_queue,greater > pq;
    pq.push({0,1});
    while(!pq.empty()) {
        pii tp=pq.top();pq.pop();
        int u=tp.se;
        if(d[u]!=tp.fi) continue;
        for(int i=hd[u];~i;i=nt[i]) {
            int v=to[i];
            if(d[u]+w[i]>n>>m&&(n+m)) {
        init();
        for(int i=1;i<=m;i++) {
            int a,b,c;
            cin>>a>>b>>c;
            add(a,b,c);
            add(b,a,c);
        }
        dij();
    }
    return 0;
}

 

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