I'm asked to find the highest frequency from an array of elements and all elements with said frequency. My code seem to work just fine but it seems to have a mistake somewhere when i submit it. Can anyone help me find the error?

Format Input: The first line contains an integer T stating the number of test cases. For each test case, the first line contains a single integer N which indicate the number of element in the array. The next line contains N integers Xi (1≤i≤N) which indicate ith element in the array.

Format Output: Consists of T lines where each line has the format “Case #X: Y ”, where X is the test case number starting at 1 and Y is the highest frequency. Next line contains all elements which have that frequency sorted in ascending order.

Constraints: 1 ≤ T ≤ 20 | 2 ≤ N ≤ 20.000 | 1 ≤ Xi ≤ 2 × 10^5

Sample Input:

3
8
1 1 2 2 3 4 5 5
8
5 5 4 3 2 2 1 1 
4
1 1 1 3

Sample Output:

Case #1: 2
1 2 5
Case #2: 2
1 2 5
Case #3: 3
1

Here is my code:

#include <stdio.h>

int main() {
    int T, N[20];

    scanf("%d", &T); getchar();
    
    int A[T][20000];
    
    
    
    for (int i = 0; i<T; i  ) {
        scanf("%d", &N[i]); getchar();
        for (int j = 0; j<N[i]; j  ) {
            scanf("%d", &A[i][j]); getchar();
        }
        
        int X = 0;
        
        for (int j = 0; j<N[i]; j  ) {
            for (int k = j   1; k<N[i]; k  ) {
                if (A[i][k]<A[i][j]) {
                    X = A[i][j];
                    A[i][j] = A[i][k];
                    A[i][k] = X;
                }
            }
        }
    }
    
    int f[20000];
    
    for (int i = 0; i<T; i  ) {
        int c = 0, mc = 0;
        
        for (int j = 0; j<N[i]; j  ) {
            c = 1;
            if(A[i][j] != -1) {
                for (int k = j 1; k<N[i]; k  ) {
                    if (A[i][j] == A[i][k]) {
                        c  ;
                        A[i][k] = -1;
                        
                    }   
                }
                
                f[j]=c;
            }   
            if (c>mc) {
                    mc = c;
                }
        }
        printf("Case #%d: %d\n", i 1, mc);
        
        for (int j = 0; j<N[i]; j  ) {
            if (A[i][j] != -1) {
                if (f[j] == mc) {
                    printf ("%d", A[i][j]);
                    if (j<N[i]-1) {
                        printf(" ");
                    }
                }
                
            }
            
        }
        
        printf("\n");
        
    }
    
    return 0;
}

EDIT So I made another code where instead of inputting all arrays at once and outputting everything at once, this code outputs the frequency and elements after i input the first arrays of numbers. But it seems like the code still have problems and i can't find where... P.s I'm pretty new to this, so i apologise for the lack of efficiency of my codes.

NEW CODE

#include <stdio.h>

int main() {
    int T, N;

    scanf("%d", &T); getchar();
    
    int A[20000];
    
    for (int i = 0; i<T; i  ) {
        scanf("%d", &N); getchar();
        for (int j = 0; j<N; j  ) {
            scanf("%d", &A[j]); getchar();
        }
        
        int X;
        
        for (int j = 0; j<N; j  ) {
            for (int k = j   1; k<N; k  ) {
                if (A[k]<A[j]) {
                    X = A[j];
                    A[j] = A[k];
                    A[k] = X;
                }
            }
        }
        
        int f[N], c = 0, mc = 0;
        
        for (int j = 0; j<N; j  ) {
            c = 1;
            if(A[j] != -1) {
                for (int k = j 1; k<N; k  ) {
                    if (A[j] == A[k]) {
                        c  ;
                        A[k] = -1;
                    }   
                }
                f[j]=c;
                if (c>mc) {
                        mc = c;
                }
            }   
        }
        printf("Case #%d: %d\n", i 1, mc);
        
        for (int j = 0; j<N; j  ) {
            if (A[j] != -1) {
                if (f[j] == mc) {
                    printf ("%d", A[j]);
                    if (j<N-1) {
                        printf(" ");
                    }
                }   
            }   
        }
        printf("\n");
    }
    
    return 0;
}

CodePudding user response：

It took me a couple of days but i finally got how to do this. Apparently, it was not as complicated as i thought... here is the working code. Thanks to everyone who helped :)

#include <stdio.h>

int main() {
    int T, N;
    
    scanf("%d", &T);
    
    for (int i = 0; i<T; i  ) {
        
        scanf("%d", &N); getchar();
        
        //INPUT elements and counting frequncy for each element
        int f[200001] = {0}, E = 0;
        for (int j = 0; j<N; j  ) {
            scanf("%d", &E); getchar();
            f[E]  ;
        }
        
        //find max frequency and how many elements with max frequency
        int max = 0, c = 0;
        for (int j = 1; j<200001; j  ) {
            
            if (f[j] == max) {
                c   ;
            }
            
            if (f[j]>max) {
                max = f[j];
                c = 1;
            }
            
        }
        
        //OUTPUT result
        printf("Case #%d: %d\n", i 1, max);
        int counter = 0;
        for (int j = 1; j<200001; j  ) {
            if (f[j] == max) {
                
                counter   ;
                if (counter<c){
                    printf("%d ", j);   
                } else {
                    printf("%d\n", j);
                }
                
            } 
        }
    }
    return 0;
}