Histogram of string in C-CodePudding

I need to find how many times letters appear in string. But I need to ignore the difference between lowercase and uppercase letters.

#include <stdio.h>
#include <string.h>
void stringHistogram(char *s) {
  int i, len = 0, counts[256] = {0};
  len = strlen(s);
  for (i = 0; i < len; i  ) {
    counts[(s[i])]  ;
  }
  for (i = 65; i < 123; i  ) {
      if(i>=91&&i<=96)continue;
    if (counts[i] > 0)
       printf("%c occurs %d times.\n", i, counts[i]);
  }
}
int main() {
  char s[] = "!!!!!PrOgraMMing -------iN C Is easy....";
  stringHistogram(s);

  return 0;
}

For example in this string "I" appears once and "i" appears twice. I want to add these two numbers and print number of them as one character. Program output should be "I appears 3 times." Could you help me modify these code?

CodePudding user response：

You do not need to use strlen and then iterate the string again. Use the correct type for sizes.

void stringHistogram(const char *s) 
{
    size_t counts[256] = {0};

    while(*s) counts[toupper((unsigned char)*s  )]  = 1;
    
    for(size_t i = 0; i < sizeof(counts) / sizeof(counts[0]); i  )
        if (counts[i] > 0)
            printf("%3zu (`%c`) occurs %zu times.\n", i, isprint((unsigned char)i) ? (char)i : '.', counts[i]);
}

CodePudding user response：

here is another solution:

#include <stdio.h>
#include <string.h>
#include <ctype.h>


void stringHistogram(char *s) {

  size_t len = 0;
  size_t counts[256] = {0};

  len = strlen(s);

  for (size_t ii = 0; ii < len;   ii) {
    size_t idx = (size_t)s[ii];
    if((idx > 64) && (idx < 91)){
      idx  = 32;
    }
    counts[idx]  ;
  }

  for (size_t ii = 0; ii < 255;   ii) {
    if(0 != isprint((char)ii)){
      if (counts[ii] > 0){
        printf("%lu [%c] occurs %lu times.\n", ii, (char)ii, counts[ii]);
      }
    }
  }
  return;
}

int main() {
  char s[] = "!!!!!PrOgraMMing -------iN C Is easy....";
  stringHistogram(s);

  return 0;
}

first like 0___________, I handled upper/lower case while counting, also I used size_t over int (it's an unsigned type)

My output is

32 [ ] occurs 4 times.
33 [!] occurs 5 times.
45 [-] occurs 7 times.
46 [.] occurs 4 times.
97 [a] occurs 2 times.
99 [c] occurs 1 times.
101 [e] occurs 1 times.
103 [g] occurs 2 times.
105 [i] occurs 3 times.
109 [m] occurs 2 times.
110 [n] occurs 2 times.
111 [o] occurs 1 times.
112 [p] occurs 1 times.
114 [r] occurs 2 times.
115 [s] occurs 2 times.
121 [y] occurs 1 times.