# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
889532 | dwuy | Ferries (NOI13_ferries) | C++14 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
/// dwuy: _,\,,,_\,__,\,,_
#include <bits/stdc++.h>
#define fastIO ios_base::sync_with_stdio(false); cin.tie(NULL)
#define file(a) freopen(a".inp","r",stdin); freopen(a".out", "w",stdout)
#define fi first
#define se second
#define endl "\n"
#define len(s) int32_t(s.length())
#define MASK(k)(1LL<<(k))
#define TASK ""
using namespace std;
typedef tuple<int, int, int> tpiii;
typedef pair<double, double> pdd;
typedef pair<int, int> pii;
typedef long long ll;
const long long OO = 1e18;
const int MOD = 1e9 + 7;
const int INF = 1e9;
const int MX = 100005;
int n, m;
int d[MX];
int rd[MX];
bitset<MX> vist;
vector<pii> G[MX];
vector<pii> rG[MX];
vector<int> cost[MX];
void fromNto1(){
priority_queue<pii, vector<pii>, greater<pii>> Q;
memset(rd, 0x3f, sizeof rd);
Q.push({0, n});
rd[n] = 0;
while(Q.size()){
int du, u;
tie(du, u) = Q.top();
Q.pop();
if(du!=rd[u]) continue;
for(pii &tmp: rG[u]){
int v, c;
tie(v, c) = tmp;
if(rd[v] > rd[u] + c){
rd[v] = rd[u] + c;
Q.push({rd[v], v});
}
}
}
}
vector<int> topo;
void dfs(int u){
vist[u] = 1;
for(pii &tmp: rG[u])if(!vist[tmp.fi]){
dfs(tmp.fi);
}
topo.push_back(u);
}
int ferries(int N, int M, int A[], int B[], int C[]){
n = N; m = M;
for(int i=0; i<m; i++){
int u, v, c;
tie(u, v, c) = {A[i], B[i], C[i]};
G[u].push_back({v, c});
rG[v].push_back({u, c});
}
fromNto1();
dfs(n);
memset(d, 0x3f, sizeof d);
d[1] = 0;
for(int u: topo){
vector<int> cost;
vector<pii> node;
for(pii &edge: G[u]){
int v, c;
tie(v, c) = edge;
cost.push_back(c);
node.push_back({rd[v], v});
}
sort(cost.begin(), cost.end(), greater<int>());
sort(node.begin(), node.end());
for(int i=0; i<(int)cost.size(); i++){
int c = cost[i];
int v = node[i].se;
d[v] = min(d[v], d[u] + c);
}
}
return d[n];
}