Create painterpartitionproblem.cpp

painterpartitionproblem.cpp

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+//program to find the minimum number of painters required to paint given number of boards
+// complexity: O(log n)
+#include<bits/stdc++.h>
+using namespace std;
+bool isVALID(int *arr,int n,int k,int mid) // function to check validity i.e. checking if no. of painters are equal or not
+{
+    int painter=1;
+    int sum=0;
+    for(int i=0;i<n;i++)
+    {
+        sum=sum+arr[i];
+        if(sum>mid)
+        {
+            painter++;
+            sum=arr[i];
+        }
+        if(painter>k)
+        return false;
+    }
+    return true;
+}
+int maxinarray(int *arr,int n) //returns max element of array
+{
+    int max=arr[0];
+    for(int i=1;i<n;i++)
+    {
+        if(arr[i]>=max)
+        max=arr[i];
+    }
+    return max;
+}
+int sumofallarrayelements(int *arr,int n) //returns sum of all elements of array
+{
+    int sum=0;
+    for(int i=0;i<n;i++)
+    {
+        sum=sum+arr[i];
+    }
+    return sum;
+}
+int main()
+{
+    int n,k,ans;
+    cout<<"ENTER NUMBER OF BOARDS: ";
+    cin>>n;
+    cout<<"ENTER NUMBER OF PAINTERS: ";
+    cin>>k;
+    int arr[n];
+    for(int i=0;i<n;i++)
+    {
+        cout<<"ENTER LENGTH OF BOARD "<<i+1<<" : ";
+        cin>>arr[i];
+    }
+    if(k>n)
+    printf("PAINTING NOT POSSIBLE");
+    else
+    {
+        int start=maxinarray(arr,n),end=sumofallarrayelements(arr,n);
+        while(start<=end) //binary searching for finding the minimum possible number of painters
+        {
+            int mid=start+((end-start)/2);
+            if(isVALID(arr,n,k,mid))
+            {
+                ans=mid;
+                end=mid-1;
+            }
+            else
+            start=mid+1;
+        }
+        cout<<"THE MINIMUM TIME REQUIRED WILL BE: "<<ans<<"units";
+    } 
+}