left smallest value

Author: pranavbharadwaj007

CSES-Problem-Set/searching-sorting/learest-smaller-values.cpp

@@ -0,0 +1,32 @@
+// link : https://cses.fi/problemset/task/1645/
+
+#include<bits/stdc++.h>
+#define ll long long int
+using namespace std;
+#define MOD 1000000007
+int sumd(int _a){int res=0;while(_a){res=res+(_a%10);_a=_a/10;}return res;}
+int main() {
+    ios_base::sync_with_stdio(0);
+    cin.tie(0);
+int n;
+cin>>n;
+vector<int>arr(n);
+for(auto &it:arr){
+  cin>>it;
+}
+stack<int>st;
+for(int i=0;i<n;i++){
+  while(!st.empty() and arr[st.top()]>=arr[i]){
+    st.pop();
+  }
+  if(st.empty()){
+    cout<<0<<" ";
+  }
+  else{
+    cout<<st.top()+1<<" ";
+  }
+    st.push(i);
+}
+cout<<endl;
+ return 0;
+}