#include <bits/stdc++.h> #define ll long long #define pb push_back using namespace std; const int N=2e5; bool vis[N]; std::vector<int> graph[N] ; int parent[N]; int n; void dfs(int pos, int pa){ parent[pos]=pa; vis[pos]=true; for(int i=0; i<graph[pos].size(); i++){ int child=graph[pos][i]; if(!vis[child]){ dfs(child, pos); } } return; } int main(){ std::cin>>n; for(int i=2; i<=n; i++){ int x; std::cin>>x; graph[x].pb(i); graph[i].pb(x); } dfs(1, -1); std::stack<int> s ; while(n!=-1){ s.push(n); n=parent[n]; } while(!s.empty()){ std::cout<<s.top()<<" "; s.pop(); } return 0; }
Write, Run & Share C++ code online using OneCompiler's C++ online compiler for free. It's one of the robust, feature-rich online compilers for C++ language, running on the latest version 17. Getting started with the OneCompiler's C++ compiler is simple and pretty fast. The editor shows sample boilerplate code when you choose language as C++
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OneCompiler's C++ online compiler supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample program which takes name as input and print your name with hello.
#include <iostream>
#include <string>
using namespace std;
int main()
{
string name;
cout << "Enter name:";
getline (cin, name);
cout << "Hello " << name;
return 0;
}
C++ is a widely used middle-level programming language.
When ever you want to perform a set of operations based on a condition If-Else is used.
if(conditional-expression) {
//code
}
else {
//code
}
You can also use if-else for nested Ifs and If-Else-If ladder when multiple conditions are to be performed on a single variable.
Switch is an alternative to If-Else-If ladder.
switch(conditional-expression){
case value1:
// code
break; // optional
case value2:
// code
break; // optional
......
default:
code to be executed when all the above cases are not matched;
}
For loop is used to iterate a set of statements based on a condition.
for(Initialization; Condition; Increment/decrement){
//code
}
While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.
while (condition) {
// code
}
Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.
do {
// code
} while (condition);
Function is a sub-routine which contains set of statements. Usually functions are written when multiple calls are required to same set of statements which increases re-usuability and modularity. Function gets run only when it is called.
return_type function_name(parameters);
function_name (parameters)
return_type function_name(parameters) {
// code
}