#include #include #include using namespace std; using i64 = int64_t; struct edge { int to; i64 cost; }; constexpr i64 inf = 987'654'321'987'654'321LL; template void readint(T *x) { *x = 0; int c; for(;;) { c = getchar_unlocked(); switch(c) case 48: case 49: case 50: case 51: case 52: case 53: case 54: case 55: case 56: case 57: goto num; } num: for(;;) { switch(c) { case 48: case 49: case 50: case 51: case 52: case 53: case 54: case 55: case 56: case 57: *x *= 10; *x += c - 48; break; default: return; } c = getchar_unlocked(); } } int main(void) { int N, M; readint(&N); readint(&M); vector> G(N, vector()); for(int i=0; i> cost(N, vector(2, inf)); cost[0][0] = 0; cost[0][1] = 0; vector> inque(N, vector(2, false)); inque[0][0] = true; // 頂点、チケットを使ったか queue> que; que.emplace(0, false); while(!que.empty()) { auto [v, used] = que.front(); que.pop(); inque[v][used] = false; for(edge &e : G[v]) { // チケットを使わない if(cost[e.to][used] > cost[v][used] + e.cost) { cost[e.to][used] = cost[v][used] + e.cost; if(!inque[e.to][used]) { inque[e.to][used] = true; que.emplace(e.to, used); } } // チケットを使う if(!used && cost[e.to][true] > cost[v][false]) { cost[e.to][true] = cost[v][false]; if(!inque[e.to][true]) { inque[e.to][true] = true; que.emplace(e.to, true); } } } } for(int v=0; v