在 C 中查找数组中每个元素的频率

Question

My task is to find frequency of each element, and elements are between 0 and 100. -1 for the end of input.

I have no problem with finding frequency, but there is some problem with my code, and I don't know what it is. Probably with do-while loop. I am beginner, and I hope you could help.

int main() {
  int n = 0, i = 0, a[100], c;
  int b[101] = {0};

  do {
    scanf("%d", &c);
    if (c == -1)
      break;
    else if (c < 0 || c > 100)
      printf("\nNumbers have to be between 0 i 100!\n");
    else {
      a[i] = c;
      i++;
      n++;
    }
  } while (c != -1);

  n--;
  for (i = 0; i < n; i++)
    b[a[i]]++;
  for (i = 0; i < n; i++) {
    if (b[i] != 0)
      printf("Count of %d is %d.\n", i, b[i]);
  }
}

Answer 1

for (i=0;i<n;i++){
    if (b[i]!=0)
        printf("Count of %d is %d.\n", i,  b[i]);
}

Here is an error in logic not syntax error but semantic error.

You are supposed to display all the content of the b. Since, B[] has the count of number. But, the loop start from 0 and end with n(no. of data).

So, just make a change like this.

for (i=0;i<101;i++){
    if (b[i]!=0)
        printf("Count of %d is %d.\n", i,  b[i]);
}

And, the second thing is you don't need to decrease the value of n.

Just, Remove

n--;