"Routine training"paths and Trees (codeforces Round 301 Div.2 E)

Test instructions and Analysis code

#include <bits/stdc++.h> #define MP make_pair#define PB emplace_back#define fi first#define se second#define ZERO (x ) memset ((x), 0, sizeof (x)) #define ALL (x) (x). Begin (), (x). End () #define REP (I, A, b) for (Reptype i = (a); I <= (b); ++i ) #define PER (I, a, b) for (Reptype i = (a); I >= (b); i) #define Quickio Ios::sync_with_stdio (FAL     SE);                      Cin.tie (0);    Cout.tie (0); using namespace std;using ll=long long;using reptype=int;struct edge{int u, v;    ll W;         Edge () {} edge (int _u, int _v, LL _w): U (_u), V (_v), W (_w) {} BOOL operator < (const edge& RHS) Const {        if (W==RHS.W) {return (U==RHS.U)?v<rhs.v:u<rhs.u;}    else {return w<rhs.w;} }};const int maxn=300005;vector<edge> edges;vector<int> G[maxn];voidadd_edge (int u, int v, ll W) {edges.    PB (U, V, W); G[u]. PB (int (edges.size ())-1);} ll Dist[maxn];int PRE[MAXN]; Pre:last Edgevoiddijkstra (int start) {memset (PRE, -1, sizeof (pre));    memset (Dist, 0x3f, sizeof (Dist));    Using P=pair<ll, int>; Priority_queue<p, Vector<p>, greater<> > PQ;    <dist, Pnt>: Dagen dist[start]=0;    Pq.push (MP (0, start));        while (!pq.empty ()) {Auto Now=pq.top (); Pq.pop ();        int u=now.se;        if (dist[u]<now.fi) {continue;}            Rep (i, 0, int (g[u].size ())-1) {int v=edges[g[u][i]].v;            ll W=EDGES[G[U][I]].W;                if (dist[v]>dist[u]+w) {dist[v]=dist[u]+w;                Pre[v]=g[u][i];            Pq.push (MP (dist[v], v));         } else if (dist[v]==dist[u]+w && edges[pre[v]].w>edges[g[u][i]].w) {pre[v]=g[u][i];}    }}}intmain () {int n, m;    scanf ("%d%d", &n, &m);        Rep (i, 1, m) {int u, v;        ll W;        scanf ("%d%d%lld", &u, &v, &w);        Add_edge (U, V, W);    Add_edge (V, U, W); } int stp; ScaNF ("%d", &AMP;STP);    Dijkstra (STP);    ll Ans=0;    Rep (i, 1, N) if (I!=STP) {ANS+=EDGES[PRE[I]].W;}    printf ("%lld\n", ans);    Rep (i, 1, N) if (I!=STP) {printf ("%d", pre[i]/2+1);}    printf ("\ n"); return 0;}

Daily training "paths and Trees (codeforces Round 301 Div.2 E)