CPP

count occurrences of character in string c++

std::string s = "a_b_c";
size_t n = std::count(s.begin(), s.end(), '_'); // n=2

letter occurrence in string c++

#include<bits/stdc++.h>
using namespace std;

 
int main(){
  int cnt=0;
   string s;
   cin>>s;
   int alpha[26]={0},i=0,j;
   while(s[i]!=''){
     if(s[i]>='a'&& s[i]<='z'){
       j=s[i]-'a';
       alpha[j]++;
     }
     i++;
   }
  for(int i=0;i<26;i++){
    if(alpha[i]>=1){
      cout<<(char)(i+'a')<<" : "<<alpha[i]<<endl;
    }
  }
  
  return 0;
}

find no of occurences of each letter in string c++

void countCharImproved(char *str) {
    std::map<char, int> count;
    int l = strlen(str);
    for(int i=0; i<l; i++) {
        count[str[i]]++;
    }
    for(const auto kvp : count) {
        std::cout << kvp.first << " occurs " << kvp.second << " times
";
    }
}

How do you count the occurrence of a given character in a string? c++

#include <iostream>
#include <algorithm>

int main(){
  std::string str;
  std::getline(std::cin, str);
  for 
    (char target: 
      {'a','b','c','d','e','f','g','h','i','j','k','l',
      'm','n','o','p','q','r','s','t','u','v','w','x','y','z'})
  {
    size_t num_target = std::count(str.begin(), str.end(), target);
    if
      (num_target>=1)
      std::cout << target <<" : " << num_target << '
';
  }
  return 0;
}