标签：des style blog io ar color sp for strong
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 is only 3 characters left in the file.
By using the read4 API, implement the function int read(char *buf, int n) that reads n characters from the file.
Note:
The read function will only be called once for each test case.
Solution:
1 /* The read4 API is defined in the parent class Reader4. 2 int read4(char[] buf); */ 3 4 public class Solution extends Reader4 { 5 /** 6 * @param buf Destination buffer 7 * @param n Maximum number of characters to read 8 * @return The number of characters read 9 */ 10 public int read(char[] buf, int n) { 11 char[] tempBuf = new char[4]; 12 int left = n; 13 while (left>0){ 14 int num = read4(tempBuf); 15 //if the read number is larger then what we need, then we just put the left number of chars into buf. 16 int end = Math.min(num,left); 17 for (int i=0;i<end;i++){ 18 buf[n-left] = tempBuf[i]; 19 left--; 20 } 21 22 //If reach EOF. 23 if (left>0 && num<4) break; 24 } 25 26 return n-left; 27 28 } 29 }
Leetcode-Read N Characters Given Read4
标签：des style blog io ar color sp for strong
原文地址：http://www.cnblogs.com/lishiblog/p/4160859.html
