dijkstra's algorithm

Dijsktra.cpp

@@ -0,0 +1,57 @@
+//g++  5.4.0
+
+#include <bits/stdc++.h>
+#define ll long long 
+#define mod 1000000007
+#define INF mod*mod
+using namespace std;
+vector<pair<ll,ll>>g[100001];
+ll n;
+void dij(ll s)
+{
+    //ll i;
+    vector<ll>dis(100001,INT_MAX);
+    //cout<<INF<<endl;
+    dis[s]=0;
+    set<pair<ll,ll>>st;
+    st.insert(make_pair(0,s));
+    while(!st.empty())
+    {
+        pair<ll,ll>tmp=*(st.begin());
+        ll u=tmp.second;
+        st.erase(st.begin());
+        for(auto i:g[u])
+        {
+            ll v=i.first;
+            ll w=i.second;
+            if(dis[v]>dis[u]+w)
+            {
+                /*if(dis[v]!=INF)
+                {
+                    st.erase(st.find(make_pair(dis[v],v)));
+                }*/
+                dis[v]=dis[u]+w;
+                st.insert(make_pair(dis[v],v));
+            }
+
+        }
+    }
+    for(ll i=1;i<=n;i++)
+    {
+        cout<<dis[i]<<" ";
+    }
+    return ;
+}
+int main()
+{
+    ll t,i,j,m,u,v,w,s;
+    cin>>n>>m;
+    while(m--)
+    {
+        cin>>u>>v>>w;
+        g[u].push_back(make_pair(v,w));
+        g[v].push_back(make_pair(u,w));
+    }
+    cin>>s;
+    dij(s);
+}