按字母顺序找出子串的个数
给定一串由小写字母组成的长度
。任务是找到字符按字母顺序出现的子字符串的数量。子字符串的最小允许长度为 2。
示例 :
Input : str = "refjhlmnbv"
Output : 2
Substrings are: "ef", "mn"
Input : str = "qwertyuiopasdfghjklzxcvbnm"
Output : 3
对于按字母顺序排列的子串，其字符的顺序与英文字母相同。此外，此类子字符串中连续字符的 ASCII 值相差 1。为了找到按字母顺序排列的子字符串的总数，遍历给定的字符串并比较两个相邻的字符，如果它们按字母顺序排列，则递增结果，然后找到字符串中与前一个字符不按字母顺序排列的下一个字符。 算法: 迭代字符串长度:
- 如果 str[i]+1 == str[i+1] ->将结果增加 1，并重复该字符串直到下一个不按字母顺序的字符
- 否则继续
以下是上述方法的实现:
C++
// CPP to find the number of substrings
// in alphabetical order
#include <bits/stdc++.h>
using namespace std;
// Function to find number of substrings
int findSubstringCount(string str)
{
int result = 0;
int n = str.size();
// Iterate over string length
for (int i = 0; i < n - 1; i++) {
// if any two chars are in alphabetic order
if (str[i] + 1 == str[i + 1]) {
result++;
// find next char not in order
while (str[i] + 1 == str[i + 1]) {
i++;
}
}
}
// return the result
return result;
}
// Driver function
int main()
{
string str = "alphabet";
cout << findSubstringCount(str) << endl;
return 0;
}
Java 语言(一种计算机语言，尤用于创建网站)
// Java to find the number of substrings
// in alphabetical order
import java.util.*;
class Solution
{
// Function to find number of substrings
static int findSubstringCount(String str)
{
int result = 0;
int n = str.length();
// Iterate over string length
for (int i = 0; i < n - 1; i++) {
// if any two chars are in alphabetic order
if (str.charAt(i) + 1 == str.charAt(i+1)) {
result++;
// find next char not in order
while (str.charAt(i) + 1 == str.charAt(i+1)) {
i++;
}
}
}
// return the result
return result;
}
// Driver function
public static void main(String args[])
{
String str = "alphabet";
System.out.println(findSubstringCount(str));
}
}
//contributed by Arnab Kundu
Python 3
# Python3 to find the number of substrings
# in alphabetical order
# Function to find number of substrings
def findSubstringCount(str):
result = 0
n = len (str)
# Iterate over string length
for i in range (n - 1) :
# if any two chars are in alphabetic order
if (ord(str[i]) + 1 == ord(str[i + 1])) :
result += 1
# find next char not in order
while (ord(str[i]) + 1 == ord(str[i + 1])) :
i += 1
# return the result
return result
# Driver Code
if __name__ == "__main__":
str = "alphabet"
print(findSubstringCount(str))
# This code is contributed by ChitraNayal
C
using System;
// C# to find the number of substrings
// in alphabetical order
public class Solution
{
// Function to find number of substrings
public static int findSubstringCount(string str)
{
int result = 0;
int n = str.Length;
// Iterate over string length
for (int i = 0; i < n - 1; i++)
{
// if any two chars are in alphabetic order
if ((char)(str[i] + 1) == str[i + 1])
{
result++;
// find next char not in order
while ((char)(str[i] + 1) == str[i + 1])
{
i++;
}
}
}
// return the result
return result;
}
// Driver function
public static void Main(string[] args)
{
string str = "alphabet";
Console.WriteLine(findSubstringCount(str));
}
}
// This code is contributed by Shrikant13
java 描述语言
<script>
// javascript to find the number of substrings
// in alphabetical order
// Function to find number of substrings
function findSubstringCount(str)
{
var result = 0;
var n = str.length;
// Iterate over string length
for (var i = 0; i < n - 1; i++) {
// if any two chars are in alphabetic order
if (String.fromCharCode(str[i].charCodeAt(0) + 1) == str[i + 1]) {
result++;
// find next char not in order
while (String.fromCharCode(str[i].charCodeAt(0) + 1) === str[i + 1]) {
i++;
}
}
}
// return the result
return result;
}
// Driver function
var str = "alphabet";
document.write( findSubstringCount(str));
</script>
Output:
1
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