Examples of the enumeration method for finding the maximum rectangular area in a histogram

Find the maximum rectangular area in the histogram:

For example, given histogram {2,3,1,2,4,2}

Then the maximum rectangular area in the histogram is x=(3,6), |x|=3, y=2, max area=6

Think: Using Enumeration

/* Enumeration forward of current position */
publicclass Solution{
  static int histogramMaxArea( int[]a ){
     int maxS =a [0];
     for(int i =0;i <a .length;i ++){    // Enumerate backwards in order in the histogram 
       int min =a [i ];         // Record current bar and previous minimum 
       int m =0;            // Record bottom edge length 
       for(int j =i ;j >=0;j --){     // Take the largest rectangle forward in turn 
         m++;
         if( a[ j]< min){
           min= a[ j];
        }
         int s =m *min ;       // Rectangular Area Calculation 
         if( s> maxS){
           maxS= s;
        }
      }
    }
     return maxS ;
  }
  public static void main(String args[]){
     int a []={2,1,1,2};
     int maxArea =histogramMaxArea( a);
    System. out.print(maxArea );
  }
}

summary