Create infix-to-prefix&postfix_using-tree-method.cpp

Author: ps-19

infix-to-prefix&postfix_using-tree-method.cpp

@@ -0,0 +1,121 @@
+#include <bits/stdc++.h>
+//#include <ext/pb_ds/assoc_container.hpp>
+//#include <ext/pb_ds/tree_policy.hpp>
+using namespace std;
+//using namespace __gnu_pbds;
+#define fastio() ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
+#pragma GCC optimize("Ofast,no-stack-protector,unroll-loops,fast-math,O3")
+#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
+#define ll  long long
+#define int long long
+#define ld  long double
+#define endl "\n"
+#define pb  push_back
+#define fill(a,val) memset(a,val,sizeof(a))
+#define ff  first
+#define ss  second
+#define test  ll t; cin>>t; while(t--)
+#define loop(i,a,b)  for(ll i=a;i<b;i++)
+#define loopr(i,a,b) for(ll i=a;i>=b;i--)
+#define pii pair<ll,ll>
+#define all(v) v.begin(),v.end()
+//typedef tree<int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;
+
+//  order_of_key (k) : Number of items strictly smaller than k .
+//  find_by_order(k) : K-th element in a set (counting from zero).
+
+const ll mod     = 1000*1000*1000+7;
+const ll inf     = 1ll*1000*1000*1000*1000*1000*1000 + 7;
+const ll mod2    = 998244353;
+const ll N       = 1000 * 1000 + 10;
+const ld pi      = 3.141592653589793;
+ll power(ll x,ll y,ll p = LLONG_MAX ){ll res=1;x%=p;while(y>0){if(y&1)res=(res*x)%p;y=y>>1;x=(x*x)%p;}return res;}
+ll ncr(ll n,ll r,ll m){if(r>n)return 0;ll a=1,b=1,i;for(i=0;i<r;i++){a=(a*n)%m;--n;}while(r){b=(b*r)%m;--r;}return (a*power(b,m-2,m))%m;}
+
+struct Node{
+	char val;
+	Node *l,*r;
+	Node(){
+		l=NULL;
+		r=NULL;
+	}
+	Node(char x){
+		this->val=x;
+		l=NULL;
+		r=NULL;
+	}
+};
+void f(Node *u){
+	if(u==NULL) return;
+	cout<<u->val;
+	f(u->l);
+	f(u->r);
+	return;
+}
+void f2(Node *u){
+	if(u==NULL) return;
+	f2(u->l);
+	f2(u->r);
+	cout<<u->val;
+	return;
+}
+void solve(){
+	string s="(a^b^(c/d/e-f)^(x*y-m*n))";
+	// s+=")";
+	// s="("+s;
+    stack<char> c;
+    stack<Node*> p;
+    map<char,ll> mp;
+    mp['+']=1;
+    mp['-']=1;
+    mp['*']=2;
+    mp['/']=2;
+    mp['^']=3;
+    mp[')']=0;
+    for(ll i=0;i<s.length();i++){
+    	if(s[i]=='(') c.push(s[i]);
+    	else if(isalpha(s[i])){
+    		Node* u=new Node(s[i]);
+    		p.push(u);
+    	}
+    	else if(mp[s[i]]>0){
+    		while(c.size()>0 && c.top()!='(' && ((s[i]=='^' && mp[c.top()] > mp[s[i]]) || (s[i]!='^' && mp[c.top()] >= mp[s[i]]))){
+    			Node *u=new Node(c.top());
+    			c.pop();
+    			Node *t1=p.top();
+    			p.pop();
+    			Node *t2=p.top();
+    			p.pop();
+    			u->l=t2;
+    			u->r=t1;
+    			p.push(u);
+    		}
+    		c.push(s[i]);
+    	}
+    	else if(s[i]==')'){
+    		while(c.size()>0 && c.top()!='('){
+    			Node *u=new Node(c.top());
+    			c.pop();
+    			Node *t1=p.top();
+    			p.pop();
+    			Node *t2=p.top();
+    			p.pop();
+    			u->l=t2;
+    			u->r=t1;
+    			p.push(u);
+    		}
+    		c.pop();
+    	}
+    }
+    f(p.top());
+    cout<<endl;
+    f2(p.top());
+    return;
+}
+
+signed main(){
+    fastio();
+    // test
+    solve();
+    return 0;
+}