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Cod sursa(job #770437)
#include <fstream>
#include <cstring>
#include <vector>
#define NLen 0x10000
#define inf 0x7fffffff
using namespace std;
ifstream fi;
ofstream fo;
vector < pair < int, int > > G[NLen];
int DIST[NLen];
int HEAP[NLen];
int POS[NLen];
int N;
inline void Down_Heap(int nod)
{
int aux = HEAP[nod], L, R;
while(L <= HEAP[0])
{
L = nod << 1;
R = L + 1;
if(L <= HEAP[0] && R <= HEAP[0] && DIST[L] > DIST[R] && DIST[R] < DIST[ HEAP[nod] ])
{
HEAP[nod] = HEAP[R];
POS[ HEAP[nod] ] = nod;
nod = R;
}
else
if(L <= HEAP[0] && DIST[L] < DIST[ HEAP[nod] ])
{
HEAP[nod] = HEAP[L];
POS[ HEAP[L] ] = nod;
nod = L;
}
else
{
HEAP[nod] = aux;
POS[aux] = nod;
return;
}
}
}
inline void Up_Heap(int nod)
{
int aux = HEAP[nod];
for(; nod > 1 && DIST[ HEAP[nod >> 1] ] > DIST[ HEAP[nod] ]; nod >>= 1)
{
HEAP[nod] = HEAP[nod >> 1];
POS[ HEAP[nod] ] = nod;
}
HEAP[nod] = aux;
POS[aux] = nod;
}
inline void Pop_Heap(int nod)
{
HEAP[nod] = HEAP[ HEAP[0] -- ];
POS[ HEAP[nod] ] = nod;
Down_Heap(POS[ HEAP[nod] ]);
}
inline void Push_Heap(int nod)
{
HEAP[ ++ HEAP[0] ] = nod;
POS[nod] = HEAP[0];
Up_Heap(HEAP[0]);
}
inline void dij(int nod)
{
int USE[NLen];
for(int i = 0; i <= N; ++ i) DIST[i] = inf;
memset(HEAP, 0, sizeof(HEAP));
memset(POS, 0, sizeof(POS));
DIST[nod] = 0;
HEAP[0] = 1;
HEAP[1] = 1;
POS[1] = 1;
while(HEAP[0])
{
nod = HEAP[1];
Pop_Heap(1);
for(int i = 0; i < G[nod].size(); ++ i)
if(DIST[ G[nod][i].first ] == inf)
{
DIST[ G[nod][i].first ] = DIST[nod] + G[nod][i].second;
Push_Heap(G[nod][i].first);
}
else
if(DIST[ G[nod][i].first ] > DIST[nod] + G[nod][i].second)
{
DIST[ G[nod][i].first ] = DIST[nod] + G[nod][i].second;
Up_Heap(POS[ G[nod][i].first ]);
}
}
}
int main()
{
int M, x, y, c;
fi.open("dijkstra.in");
fi >> N >> M;
for(; M -- ; )
{
fi >> x >> y >> c;
G[x].push_back(make_pair(y, c));
}
fi.close();
dij(1);
fo.open("dijkstra.out");
for(int i = 2; i <= N; ++ i)
if(DIST[i] == inf) DIST[i] = 0;
for(int i = 2; i <= N; ++ i) fo << DIST[i] << ' ';
fo << '\n';
fo.close();
return 0;
}