practice 26-Jan-2020

Author: sureshmangs

algorithms/searching/binary_search.cpp

@@ -0,0 +1,33 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+int binarySearch(int a[],int n, int item){
+    int first=0, last=n,mid;
+
+    while(first<=last){
+        mid=(first+last)/2;
+        if(item==a[mid]) return mid;
+        else if(item < a[mid]) last=mid-1;
+        else first=mid+1;
+    }
+    return -1;
+}
+
+int main()
+{
+    ios_base::sync_with_stdio(false);
+    cin.tie(NULL);
+    int n;
+    cin>>n;
+    int a[n];
+    for(int i=0;i<n;i++){
+        cin>>a[i];
+    }
+    sort(a,a+n);
+    int item;
+    cin>>item;
+    int index=binarySearch(a,n,item);
+    if(index>=0) cout<<"Found at index "<<index;
+    else cout<<"Not found";
+return 0;
+}