Problem:
Score : 500 points

Problem Statement

We have a two-dimensional grid with H \times W squares. There are M targets to destroy in this grid - the position of the i-th target is \left(h_i, w_i \right).

Takahashi will choose one square in this grid, place a bomb there, and ignite it. The bomb will destroy all targets that are in the row or the column where the bomb is placed. It is possible to place the bomb at a square with a target.

Takahashi is trying to maximize the number of targets to destroy. Find the maximum number of targets that can be destroyed.

Constraints

All values in input are integers.

1 \leq H, W \leq 3 \times 10^5

1 \leq M \leq \min\left(H\times W, 3 \times 10^5\right)

1 \leq h_i \leq H

1 \leq w_i \leq W

\left(h_i, w_i\right) \neq \left(h_j, w_j\right) \left(i \neq j\right)

Input

Input is given from Standard Input in the following format:

H W M
h_1 w_1
\vdots
h_M w_M

Output

Print the answer.

Sample Input 1

2 3 3
2 2
1 1
1 3

Sample Output 1

3

We can destroy all the targets by placing the bomb at \left(1, 2\right).

Sample Input 2

3 3 4
3 3
3 1
1 1
1 2

Sample Output 2

3

Sample Input 3

5 5 10
2 5
4 3
2 3
5 5
2 2
5 4
5 3
5 1
3 5
1 4

Sample Output 3

6

Solution in Java (OpenJDK 1.8.0) (judge verdict: Runtime Error)




import java.util.*;
import java.io.*;

public class Main 

{ 

	 static FastReader sc=new FastReader(); 
	 
		  public static void main(String[] args) 
    {
			  
			  long h=l();
			  long w=l();
			  long m=l();
			  int A[][]=new int[3000001][3000001];
			  long row[]=new long[3000001];
			  long col[]=new long[3000001];
			  while(m-- > 0) {
				  long r=l();
				  long c=l();
				  row[(int)r]++;
				  col[(int)c]++;
				  A[(int)r][(int)c]=1;
				  
			  }
			  long maxr=Integer.MIN_VALUE,maxc=Integer.MIN_VALUE;
			  int indr=-1,indc=-1;
			  int cc=-1;
			  for(int i=0;i<row.length;i++) {
				  if(row[i]>maxr) {
					  maxr=row[i];
					  indr=i;
				  }
			  }
			  for(int i=0;i<col.length;i++) {
				  if(col[i]>=maxc) {
					  maxc=col[i];
					  indc=i;
					  if(cc==-1)
						  cc=indc;
					  if(A[indr][indc]!=1)
						  cc=indc;
					  if(col[cc]!=maxc)
						  cc=i;
				  }
			  }
			  if(indr>0&&indr<h && cc>0&&cc<w &&A[indr][cc]!=1)
				  System.out.println(maxr+maxc);
			  else
				  System.out.println(maxr+maxc-1);
				  
			  
			  
			  
			  
			  
			  
			  
			  
			  
			  
//			  long m=l();
//			  int A[][]=new int[h+h][w+w];
//			  int rr[]=new int[(int)m];
//			  int ccc[]=new int[(int)m];
//			  for(int i=0;i<m;i++) {
//				  int r=i();
//				  if(row.containsKey(r)) {
//					  row.put(r,row.get(r)+1);
//				  }
//				  else
//					  row.put(r,(long)1);
//				  int c=i();
//				  if(col.containsKey(c)) {
//					  col.put(c,col.get(c)+1);
//				  }
//				  else
//					  col.put(c,(long)1);
//				  
//				  rr[i]=r;
//				  ccc[i]=c;
//				  A[r][c]=1;
//			  }
//			  long maxr=0;
//			  int keyr=0;
//			  for(int i : rr) {
//				  long g=row.get(i);
//				  if(g>maxr) {
//					  maxr=g;
//					  keyr=i;
//				  }
//			  }
//
//			  long maxc=0;
//			  int keyc=-1;
//			  int keycc=ccc[0];
//			  for(int i : ccc) {
//				  long cc=col.get(i);
//				  if(cc>=maxc) {
//					keyc=i;
//					if(keycc==-1)
//						keycc=i;
//					  maxc=cc;
//					if(A[keyr][i]!=1)
//						keycc=i;
//					if(col.get(keycc)!=maxc)
//						keycc=i;
//				  }
//				  
//			  }
////			  if(keycc==-1)
////				  keycc=keyc;
////			  //System.out.println(keyr+" "+keycc);
////			  long res=maxc+maxr;
////			  if(A[keyr][keycc]!=1)
////			  System.out.println(res);
////			  else
//				  System.out.println(res-1);  
//			  
			  
    }

		  static int gcd(int a, int b) 
		    { 
		      if (b == 0) 
		        return a; 
		      return gcd(b, a % b);  
		    } 

		  static boolean is(int x)  
		    { 
		        double sr = Math.sqrt(x); 
		      
		        return ((sr - Math.floor(sr)) == 0); 
		    } 

static void input(int A[]) {
	   for(int i=0;i<A.length;i++) {
		   A[i]=sc.nextInt();
	   }
   }
static void input(int A[],int B[]) {
	   for(int i=0;i<A.length;i++) {
		   A[i]=sc.nextInt();
		   B[i]=sc.nextInt();
	   }
}
     static int i() {
    	 return sc.nextInt();
     }
     static String s() {
    	 return sc.next();
     }
     static long l() {
    	 return sc.nextLong();
     }  
        static void shuffleArray(int[] arr){
        int n = arr.length;
        Random rnd = new Random();
        for(int i=0; i<n; ++i){
            int tmp = arr[i];
            int randomPos = i + rnd.nextInt(n-i);
            arr[i] = arr[randomPos];
            arr[randomPos] = tmp;
        }   
}
  
        
        
    static class FastReader 
    { 
        BufferedReader br; 
        StringTokenizer st; 
  
        public FastReader() 
        { 
            br = new BufferedReader(new
                     InputStreamReader(System.in)); 
        } 
  
        String next() 
        { 
            while (st == null || !st.hasMoreElements()) 
            { 
                try
                { 
                    st = new StringTokenizer(br.readLine()); 
                } 
                catch (IOException  e) 
                { 
                    e.printStackTrace(); 
                } 
            } 
            return st.nextToken(); 
        } 
  
        int nextInt() 
        { 
            return Integer.parseInt(next()); 
        } 
  
        long nextLong() 
        { 
            return Long.parseLong(next()); 
        } 
  
        double nextDouble() 
        { 
            return Double.parseDouble(next()); 
        } 
  
        String nextLine() 
        { 
            String str = ""; 
            try
            { 
                str = br.readLine(); 
            } 
            catch (IOException e) 
            { 
                e.printStackTrace(); 
            } 
            return str; 
        } 
    } 
}