计算重复字符串中某个字符的出现次数

给定一个整数 N 和一个小写字符串。字符串无限重复。任务是找出给定字符x 在前 N 个字母中出现的次数。
例子：

Input : N = 10 str = "abcac"
Output : 4
Explanation: "abcacabcac" is the substring from the infinitely repeated string. In first 10 letters 'a' occurs 4  times.
          
Input: N = 10, str = "aba"
Output : 7

方法：
1. 查找给定字符串中出现的字符“a”。
2. 找出找出“a”出现所需的重复次数。
3. 将单个字符串出现次数乘以重复次数。
4. 如果给定的 n 不是给定字符串大小的倍数，那么我们将在剩余的子字符串中找到出现的“a”。
以下是上述方法的实现：

C++

// CPP program to find the occurrences of
// character x in the infinite repeated string
// upto length n
#include 
using namespace std;
 
// Function to count the character 'a'
int countChar(string str, char x)
{
    int count = 0, n = 10;
    for (int i = 0; i < str.size(); i++)
        if (str[i] == x)
            count++;
 
    // atleast k repetition are required
    int repetitions = n / str.size();
    count = count * repetitions;
 
    // if n is not the multiple of the string size
    // check for the remaining repeating character.
    for (int i = 0; i < n % str.size(); i++) {
        if (str[i] == x)
            count++;
    }
 
    return count;
}
 
// Driver code
int main()
{
    string str = "abcac";
    cout << countChar(str, 'a');
    return 0;
}
 
// This code is contributed by Surendra_Gangwar

Java

// Java program to find the occurrences
// of character x in the infinite
// repeated string upto length n
import java.util.*;
import java.lang.*;
 
class GFG
{
// Function to count the character 'a'
static int countChar(String str, char x)
{
    int count = 0;
    int n = 10;
    for (int i = 0; i < str.length(); i++)
        if (str.charAt(i) == x)
            count++;
 
    // atleast k repetition are required
    int repetitions = n / str.length();
    count = count * repetitions;
 
    // if n is not the multiple of the
    // string size check for the remaining
    // repeating character.
    for (int i = 0;
            i < n % str.length(); i++)
    {
        if (str.charAt(i) == x)
            count++;
    }
 
    return count;
}
 
// Driver code
public static void main(String args[])
{
    String str = "abcac";
    System.out.println(countChar(str, 'a'));
}
}
 
// This code is contributed
// by Akanksha Rai

Python3

# Python3 program to find the occurrences of
# character x in the infinite repeated string
# upto length n
 
# Function to count the character 'a'
def countChar(str, x):
    count = 0
    for i in range(len(str)):
        if (str[i] == x) :
            count += 1
    n = 10
     
    # atleast k repetition are required
    repetitions = n // len(str)
    count = count * repetitions
 
    # if n is not the multiple of the
    # string size check for the remaining
    # repeating character.
    l = n % len(str)
    for i in range(l):
        if (str[i] == x):
            count += 1
    return count
 
# Driver code
str = "abcac"
print(countChar(str, 'a'))
 
# This code is contributed
# by sahishelangia

C#

// C# program to find the occurrences
// of character x in the infinite
// repeated string upto length n
using System;
 
class GFG
{
// Function to count the character 'a'
static int countChar(string str, char x)
{
    int count = 0;
    int n = 10;
    for (int i = 0; i < str.Length; i++)
        if (str[i] == x)
            count++;
 
    // atleast k repetition are required
    int repetitions = n / str.Length;
    count = count * repetitions;
 
    // if n is not the multiple of the
    // string size check for the remaining
    // repeating character.
    for (int i = 0;
             i < n % str.Length; i++)
    {
        if (str[i] == x)
            count++;
    }
 
    return count;
}
 
// Driver code
public static void Main()
{
    string str = "abcac";
    Console.WriteLine(countChar(str, 'a'));
}
}
 
// This code is contributed
// by Akanksha Rai

PHP

Javascript

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