Solved Day4 Q1

Author: Humanshere

Problems/Data-structures/Day-04/sol/Himansh_Arora/Solution1.cpp

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+//Problem Link- https://codeforces.com/problemset/problem/1997/C
+//Submission Link- https://codeforces.com/problemset/submission/1997/355848236
+//checked greedy pairing of current index with last one in stack
+//time complexity- O(n)
+
+#include <bits/stdc++.h>
+using namespace std;
+
+void solve() {
+    int n;
+    string s;
+    cin>>n>>s;
+    stack <pair<char,int>> s1;
+    int cost=0;
+    for(int i=0;i<n;i++){
+        if(s1.empty()){
+            s1.push({s[i],i});
+        }else{
+            if(s[i]==')'&&s1.top().first=='_'){
+                cost+=(i-s1.top().second);
+                s1.pop();
+            }else if(s[i]=='('&&s1.top().first=='_'){
+                s1.push({s[i],i});
+            }else if(s[i]=='_'&&s1.top().first=='('){
+                cost+=(i-s1.top().second);
+                s1.pop();            
+            }
+        }
+    }
+
+     cout<<cost<<endl;
+}
+
+signed main() {
+    
+    int t;
+    cin >> t;
+    
+    while (t--) {
+        solve();
+    }
+    
+    return 0;
+}