Chúng tôi được yêu cầu viết một hàm JavaScript nhận vào một chuỗi và trả về một chuỗi mới chỉ chứa các từ xuất hiện nhiều lần trong chuỗi ban đầu
Ví dụ. Nếu chuỗi đầu vào là -
const str = "big black bug bit a big black dog on his big black nose";
Sau đó, đầu ra phải là -
const output = "big black";
Thí dụ
Hãy viết mã cho chức năng này -
const str = "big black bug bit a big black dog on his big black nose"; const findDuplicateWords = str => { const strArr = str.split[" "]; const res = []; for[let i = 0; i < strArr.length; i++]{ if[strArr.indexOf[strArr[i]] !== strArr.lastIndexOf[strArr[i]]]{ if[!res.includes[strArr[i]]]{ res.push[strArr[i]]; }; }; }; return res.join[" "]; }; console.log[findDuplicateWords[str]];
đầu ra
Đầu ra trong bảng điều khiển. -
big black
Trong bài viết này, chúng ta được cung cấp một chuỗi, nhiệm vụ của chúng ta là tìm sự xuất hiện của một ký tự trong chuỗi với sự trợ giúp của một hàm do người dùng định nghĩa.
Example: Input : "hello" Output : h occur 1 times e occur 1 times l occur 2 times o occur 1 times Explanation : here "hello" have 1 h, so it have 1 value. as same e have 1, l have 2 , o have 1. Example 2: Input : "did" Output: d occur 2 times i occur 1 times
Cách tiếp cận 1. Theo cách tiếp cận này, chúng tôi sử dụng cấu trúc dữ liệu bản đồ để lưu trữ số lần các ký tự xuất hiện
- Đầu tiên, chúng tôi khởi tạo bản đồ bằng một khóa cho mỗi ký tự của chuỗi và giá trị cho mỗi ký tự là 0
- Chúng tôi lặp qua chuỗi và tăng giá trị của ký tự
- Cuối cùng, in khóa-giá trị của bản đồ
Thí dụ. Ví dụ này cho thấy việc sử dụng phương pháp được giải thích ở trên
Javascript
//function to print occurrence of character
function
printans[ ans ]
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times1
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times2_______5_______3
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times4
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times2_______5_______1
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times7
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times8
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times7
g occurs 2 times f occurs 1 times h occurs 1 times e occurs 1 times l occurs 2 times o occurs 1 times0
g occurs 2 times f occurs 1 times h occurs 1 times e occurs 1 times l occurs 2 times o occurs 1 times1
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times2
g occurs 2 times f occurs 1 times h occurs 1 times e occurs 1 times l occurs 2 times o occurs 1 times3
g occurs 2 times f occurs 1 times h occurs 1 times e occurs 1 times l occurs 2 times o occurs 1 times3
g occurs 2 times f occurs 1 times h occurs 1 times e occurs 1 times l occurs 2 times o occurs 1 times9
function
h occur 1 times e occur 1 times l occur 2 times o occur 1 times2
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times1
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times2_______5_______3
h occur 1 times e occur 1 times l occur 2 times o occur 1 times7
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times2_______5_______1
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times7
2h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times7
45
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times7
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times2
g occurs 2 times f occurs 1 times h occurs 1 times e occurs 1 times l occurs 2 times o occurs 1 times3
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times2
0h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times2
2
g occurs 2 times f occurs 1 times h occurs 1 times e occurs 1 times l occurs 2 times o occurs 1 times3
7
function
//function to print occurrence of character
0
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times1
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times2_______133_______4
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times2_______133_______6
//function to print occurrence of character
7h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times2_______5_______1
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times7
1
2
3h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times7
5
6h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times2
g occurs 2 times f occurs 1 times h occurs 1 times e occurs 1 times l occurs 2 times o occurs 1 times3
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times2
function
0h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times2_______5_______1
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times7
function
4h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times7
function
6function
7 function
8h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times7
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times3
printans[ ans ]
1h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times7
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times1
g occurs 2 times f occurs 1 times h occurs 1 times e occurs 1 times l occurs 2 times o occurs 1 times1
printans[ ans ]
5h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times7
g occurs 2 times f occurs 1 times h occurs 1 times e occurs 1 times l occurs 2 times o occurs 1 times3
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times7
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times7_______5_______00
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times7
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times2
g occurs 2 times f occurs 1 times h occurs 1 times e occurs 1 times l occurs 2 times o occurs 1 times3
g occurs 2 times f occurs 1 times h occurs 1 times e occurs 1 times l occurs 2 times o occurs 1 times3
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times09
5_______11_______5_______12
6
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times15
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times16
đầu ra
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times
Cách tiếp cận 2. Trong cách tiếp cận này, chúng tôi sử dụng vòng lặp for lồng nhau để lặp qua chuỗi và đếm cho từng ký tự trong chuỗi.
- Đầu tiên, khởi tạo count với giá trị 0 cho giá trị thứ i của chuỗi
- Bây giờ chúng tôi lặp lại chuỗi nếu giá trị thứ i khớp với ký tự, tăng giá trị đếm lên 1
- Cuối cùng, in giá trị của số đếm
Thí dụ. Ví dụ này cho thấy việc sử dụng phương pháp được giải thích ở trên
Javascript
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times19
function
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times22
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times1
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times2_______5_______26
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times2_______133_______6
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times29
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times2_______5_______1
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times7
1h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times34
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times35
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times7
5
6h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times2
g occurs 2 times f occurs 1 times h occurs 1 times e occurs 1 times l occurs 2 times o occurs 1 times3
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times2_______5_______42
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times2_______5_______3
h occur 1 times e occur 1 times l occur 2 times o occur 1 times7
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times2_______5_______1
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times7
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times49
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times7
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times51
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times7
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times3
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times54
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times7
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times1
g occurs 2 times f occurs 1 times h occurs 1 times e occurs 1 times l occurs 2 times o occurs 1 times1
//function to print occurrence of character
6h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times59
g occurs 2 times f occurs 1 times h occurs 1 times e occurs 1 times l occurs 2 times o occurs 1 times1
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times1
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times62_______5_______63
6g occurs 2 times f occurs 1 times h occurs 1 times e occurs 1 times l occurs 2 times o occurs 1 times1
g occurs 2 times f occurs 1 times h occurs 1 times e occurs 1 times l occurs 2 times o occurs 1 times3
g occurs 2 times f occurs 1 times h occurs 1 times e occurs 1 times l occurs 2 times o occurs 1 times1
//function to print occurrence of character
6h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times69
g occurs 2 times f occurs 1 times h occurs 1 times e occurs 1 times l occurs 2 times o occurs 1 times1
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times1
5
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times73
g occurs 2 times f occurs 1 times h occurs 1 times e occurs 1 times l occurs 2 times o occurs 1 times1
g occurs 2 times f occurs 1 times h occurs 1 times e occurs 1 times l occurs 2 times o occurs 1 times3
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times7
g occurs 2 times f occurs 1 times h occurs 1 times e occurs 1 times l occurs 2 times o occurs 1 times3
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times7
//function to print occurrence of character
6h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times80
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times7_______5_______82
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times7
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times2
g occurs 2 times f occurs 1 times h occurs 1 times e occurs 1 times l occurs 2 times o occurs 1 times3
g occurs 2 times f occurs 1 times h occurs 1 times e occurs 1 times l occurs 2 times o occurs 1 times3
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times09
5_______93_______5_______94
6
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times97
h occurs 1 times e occurs 1 times l occurs 3 times o occurs 2 times w occurs 1 times r occurs 1 times d occurs 1 times16
đầu ra
g occurs 2 times f occurs 1 times h occurs 1 times e occurs 1 times l occurs 2 times o occurs 1 times
Cách tiếp cận-3. Trong cách tiếp cận này, chúng tôi sẽ sử dụng vòng lặp for để lặp qua chính chuỗi hoàn chỉnh. Đây là cách tiếp cận đơn giản nhất mà chúng tôi có thể thực hiện để tìm ra nhiệm vụ kết quả