Leetcode Read N characters Given Read4

The API: int read4(char *buf) reads 4 characters at a time from a file.

The return value is the actual number of characters read. For example, it returns 3 if there are only 3 characters left in the file.

read4by using the API, implement the function that int read(char *buf, int n) reads n characters from the file.

Note:
The function is only being read called once for each test case.

Problem Solving Ideas:

start to understand the test instructions error, read 4 characters each time, not read from the BUF, but read from the file, deposited into BUF. If Read4 < 4, the end of the file is read. At the same time think of File.length > N, each time you want to determine the correct length to read into the BUF, that is max.min (count, N-total)

Java Code:

/*The read4 API is defined in the parent class Reader4. int Read4 (char[] buf); */ Public classSolutionextendsReader4 {/**     * @parambuf Destination Buffer *@paramn Maximum number of characters to read *@returnThe number of characters read*/     Public intReadChar[] buf,intN) {BooleanEOF =false;//End of File        Char[] temp =New Char[4]; intTotal = 0;  while(!eof && Total <N) {            intCount =read4 (temp); if(Count < 4) {EOF=true; }            //get the actual countCount = Math.min (count, N-Total );  for(inti = 0; i< count; i++) {Buf[total++] =Temp[i]; }        }        returnTotal ; }}

Reference:

1. Https://leetcode.com/discuss/44743/another-accepted-java-solution

2. http://bangbingsyb.blogspot.com/2014/11/leetcode-read-n-characters-given-read4.html

Leetcode Read N characters Given Read4