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Original file line number Diff line number Diff line change
Expand Up @@ -118,7 +118,29 @@ tags:
#### Python3

```python

class Solution:
def minTime(self, n: int, edges: List[List[int]]) -> int:
minReachTime = [inf] * n
minReachTime[0] = 0

nodeEdges = [[] for _ in range(n)]
for edge in edges:
nodeEdges[edge[0]].append(edge)

reachTimeHeap = [(0, 0)]
while reachTimeHeap:
curTime, node = heappop(reachTimeHeap)
if node == n - 1:
return curTime

for edge in nodeEdges[node]:
if curTime <= edge[3]:
destTime = max(curTime, edge[2]) + 1
if minReachTime[edge[1]] > destTime:
minReachTime[edge[1]] = destTime
heappush(reachTimeHeap, (destTime, edge[1]))

return -1
```

#### Java
Expand All @@ -130,13 +152,143 @@ tags:
#### C++

```cpp

class Solution {
vector<vector<vector<int>>> adj;
vector<int> sol;
priority_queue<pair<int,int> ,vector<pair<int,int>>,greater<>> pq;
void pushNeighbours(int node,int curr){
for(auto it : adj[node]){
int temp = it[0] , start = it[1],end = it[2],newTime = curr+1;
if(curr<start) newTime = start+1;
if(newTime < sol[temp] && newTime-1<=end){
pq.push({newTime,temp});
sol[temp] = newTime;
}
}
}
public:
int minTime(int n, vector<vector<int>>& edges) {
adj = vector<vector<vector<int>>>(n);
for(auto it: edges)
adj[it[0]].push_back({it[1],it[2],it[3]});
sol = vector<int> (n,INT_MAX);
sol[0]=0;
for(pq.push({0,0});!pq.empty();pq.pop())
pushNeighbours(pq.top().second,pq.top().first);
if(sol[n-1] == INT_MAX) return -1;
return sol[n-1];
}
};
const auto __ = []() {
struct ___ {
static void _() {
std::ofstream("display_runtime.txt") << 0 << '\n';
std::ofstream("display_memory.txt") << 0 << '\n';
}
};
std::atexit(&___::_);
return 0;
}();
```

#### Go

```go

import "container/heap"

func minTime(n int, edges [][]int) int {
graph := make([][][3]int, n)
for _, edge := range edges {
u, v, start, end := edge[0], edge[1], edge[2], edge[3]
graph[u] = append(graph[u], [3]int{v, start, end})
}

dist := make([]int, n)
for i := range dist {
dist[i] = -1
}
dist[0] = 0

pq := &PriorityQueue{}
heap.Init(pq)
heap.Push(pq, &Item{value: 0, priority: 0})

for pq.Len() > 0 {
item := heap.Pop(pq).(*Item)
u := item.value
d := item.priority

if d > dist[u] && dist[u] != -1{
continue
}


if u == n-1{
continue
}


for _, edge := range graph[u] {
v, start, end := edge[0], edge[1], edge[2]

wait := 0
if d < start {
wait = start - d
}

if d + wait <= end {
newDist := d + wait + 1
if dist[v] == -1 || newDist < dist[v] {
dist[v] = newDist
heap.Push(pq, &Item{value: v, priority: newDist})
}
}
}
}

return dist[n-1]
}

type Item struct {
value int // The value of the item; arbitrary.
priority int // The priority of the item in the queue.
// The index is needed to update during heap operations. It is
// maintained by the heap.Interface methods.
index int // The index of the item in the heap.
}

// A PriorityQueue implements heap.Interface and holds Items.
type PriorityQueue []*Item

func (pq PriorityQueue) Len() int { return len(pq) }

func (pq PriorityQueue) Less(i, j int) bool {
// We want Pop to give us the lowest, not highest, priority so we use less than here.
return pq[i].priority < pq[j].priority
}

func (pq PriorityQueue) Swap(i, j int) {
pq[i], pq[j] = pq[j], pq[i]
pq[i].index = i
pq[j].index = j
}

func (pq *PriorityQueue) Push(x any) {
n := len(*pq)
item := x.(*Item)
item.index = n
*pq = append(*pq, item)
}

func (pq *PriorityQueue) Pop() any {
old := *pq
n := len(old)
item := old[n-1]
old[n-1] = nil // avoid memory leak
item.index = -1 // for safety
*pq = old[0 : n-1]
return item
}
```

<!-- tabs:end -->
Expand Down
Original file line number Diff line number Diff line change
Expand Up @@ -115,7 +115,29 @@ tags:
#### Python3

```python

class Solution:
def minTime(self, n: int, edges: List[List[int]]) -> int:
minReachTime = [inf] * n
minReachTime[0] = 0

nodeEdges = [[] for _ in range(n)]
for edge in edges:
nodeEdges[edge[0]].append(edge)

reachTimeHeap = [(0, 0)]
while reachTimeHeap:
curTime, node = heappop(reachTimeHeap)
if node == n - 1:
return curTime

for edge in nodeEdges[node]:
if curTime <= edge[3]:
destTime = max(curTime, edge[2]) + 1
if minReachTime[edge[1]] > destTime:
minReachTime[edge[1]] = destTime
heappush(reachTimeHeap, (destTime, edge[1]))

return -1
```

#### Java
Expand All @@ -127,13 +149,143 @@ tags:
#### C++

```cpp

class Solution {
vector<vector<vector<int>>> adj;
vector<int> sol;
priority_queue<pair<int,int> ,vector<pair<int,int>>,greater<>> pq;
void pushNeighbours(int node,int curr){
for(auto it : adj[node]){
int temp = it[0] , start = it[1],end = it[2],newTime = curr+1;
if(curr<start) newTime = start+1;
if(newTime < sol[temp] && newTime-1<=end){
pq.push({newTime,temp});
sol[temp] = newTime;
}
}
}
public:
int minTime(int n, vector<vector<int>>& edges) {
adj = vector<vector<vector<int>>>(n);
for(auto it: edges)
adj[it[0]].push_back({it[1],it[2],it[3]});
sol = vector<int> (n,INT_MAX);
sol[0]=0;
for(pq.push({0,0});!pq.empty();pq.pop())
pushNeighbours(pq.top().second,pq.top().first);
if(sol[n-1] == INT_MAX) return -1;
return sol[n-1];
}
};
const auto __ = []() {
struct ___ {
static void _() {
std::ofstream("display_runtime.txt") << 0 << '\n';
std::ofstream("display_memory.txt") << 0 << '\n';
}
};
std::atexit(&___::_);
return 0;
}();
```

#### Go

```go

import "container/heap"

func minTime(n int, edges [][]int) int {
graph := make([][][3]int, n)
for _, edge := range edges {
u, v, start, end := edge[0], edge[1], edge[2], edge[3]
graph[u] = append(graph[u], [3]int{v, start, end})
}

dist := make([]int, n)
for i := range dist {
dist[i] = -1
}
dist[0] = 0

pq := &PriorityQueue{}
heap.Init(pq)
heap.Push(pq, &Item{value: 0, priority: 0})

for pq.Len() > 0 {
item := heap.Pop(pq).(*Item)
u := item.value
d := item.priority

if d > dist[u] && dist[u] != -1{
continue
}


if u == n-1{
continue
}


for _, edge := range graph[u] {
v, start, end := edge[0], edge[1], edge[2]

wait := 0
if d < start {
wait = start - d
}

if d + wait <= end {
newDist := d + wait + 1
if dist[v] == -1 || newDist < dist[v] {
dist[v] = newDist
heap.Push(pq, &Item{value: v, priority: newDist})
}
}
}
}

return dist[n-1]
}

type Item struct {
value int // The value of the item; arbitrary.
priority int // The priority of the item in the queue.
// The index is needed to update during heap operations. It is
// maintained by the heap.Interface methods.
index int // The index of the item in the heap.
}

// A PriorityQueue implements heap.Interface and holds Items.
type PriorityQueue []*Item

func (pq PriorityQueue) Len() int { return len(pq) }

func (pq PriorityQueue) Less(i, j int) bool {
// We want Pop to give us the lowest, not highest, priority so we use less than here.
return pq[i].priority < pq[j].priority
}

func (pq PriorityQueue) Swap(i, j int) {
pq[i], pq[j] = pq[j], pq[i]
pq[i].index = i
pq[j].index = j
}

func (pq *PriorityQueue) Push(x any) {
n := len(*pq)
item := x.(*Item)
item.index = n
*pq = append(*pq, item)
}

func (pq *PriorityQueue) Pop() any {
old := *pq
n := len(old)
item := old[n-1]
old[n-1] = nil // avoid memory leak
item.index = -1 // for safety
*pq = old[0 : n-1]
return item
}
```

<!-- tabs:end -->
Expand Down
Original file line number Diff line number Diff line change
@@ -0,0 +1,37 @@
class Solution {
vector<vector<vector<int>>> adj;
vector<int> sol;
priority_queue<pair<int,int> ,vector<pair<int,int>>,greater<>> pq;
void pushNeighbours(int node,int curr){
for(auto it : adj[node]){
int temp = it[0] , start = it[1],end = it[2],newTime = curr+1;
if(curr<start) newTime = start+1;
if(newTime < sol[temp] && newTime-1<=end){
pq.push({newTime,temp});
sol[temp] = newTime;
}
}
}
public:
int minTime(int n, vector<vector<int>>& edges) {
adj = vector<vector<vector<int>>>(n);
for(auto it: edges)
adj[it[0]].push_back({it[1],it[2],it[3]});
sol = vector<int> (n,INT_MAX);
sol[0]=0;
for(pq.push({0,0});!pq.empty();pq.pop())
pushNeighbours(pq.top().second,pq.top().first);
if(sol[n-1] == INT_MAX) return -1;
return sol[n-1];
}
};
const auto __ = []() {
struct ___ {
static void _() {
std::ofstream("display_runtime.txt") << 0 << '\n';
std::ofstream("display_memory.txt") << 0 << '\n';
}
};
std::atexit(&___::_);
return 0;
}();
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