Repetitive substrings

Check if string contains the exact same number of repetitions of every character. I.e. "aabb" - true, "aabbc" - false. Then check if removing a single character from the string can make it valid, i.e. "aabbc" - true, "aaabbbcc" - false

public boolean repnumber(String s) {
    boolean result = true;
    char prev = '\0';
    int maxcount = 0, count = 0, mincount = s.length();

   Map<Integer, Integer> frequencies = new HashMap<>();
    
    for(int i=0; i<s.length();i++) {
      char c = s.charAt(i);
      if((prev!='\0' && prev != c)) {
        if (frequencies.containsKey(count)) {
            frequencies.put(count, frequencies.get(count) + 1);
        } else {
            frequencies.put(count, 1);
        }
        count = 0;
      } 
      count++;
      prev = c;
    }  
    if (frequencies.containsKey(count)) {
        frequencies.put(count, frequencies.get(count) + 1);
    } else {
        frequencies.put(count, 1);
    }

    
    if(frequencies.size() > 2) return false; 
    if(frequencies.size() == 1) return true; 
    List<Integer> list = new ArrayList<>(frequencies.keySet());

    int max = Math.max(list.get(0), list.get(1));
    int min = Math.min(list.get(0), list.get(1));
    
    if(frequencies.get(max) == 1 && max-min == 1) return true;
    if(frequencies.get(min) == 1 && min == 1) return true;
    
    return false;    
  }

SubArray sum

In an array of non-negative intergers find a sequence of integers which sum up to the given number. I.e. [1, 2, 3], find 5 -> return [2, 3]

public int sums(int[] seq, int sum) {
    int csum = 0, right = 0, left = 0;
    boolean notfound = true;

    while(right < seq.length && notfound) {
      for(int i = right; i < seq.length; i++) {   
        csum +=seq[i];
        if(csum == sum) {left = i; notfound=false; break;}
        if(csum > sum) { csum=0; break;}
      }
      csum=0;
      right++;
      
    }

    if(notfound) {right=1; left = -1; }
    int[] res = Arrays.copyOfRange(seq,right-1, left+1);
    
    System.out.println(Arrays.toString(res));
    System.out.println(right-1);
    System.out.println(left);
    System.out.println(notfound);


    return 0;
  }