所以我做Usacogate的貪婪送禮者和使用while循環來檢查,如果該文件中的下一行是空或不是,具體!= NULL在Java while循環不工作
while((tempName = sc.nextLine()) != null){
問題是,一旦它讀取最後一行並返回到頂部以檢查是否存在下一行,Java會拋出NoSuchElementException,而不是看到沒有行並退出循環。所有其他部分都可以工作,並且代碼返回正確的答案。
我該如何解決這個問題?
public static void main(String [] args) throws IOException {
Scanner sc = new Scanner(new File("gift1.in"));
int n = sc.nextInt();
System.out.printf("n is: %d\n", n);
String[] names = new String[10];
sc.nextLine();
int[] account = new int[10];
for (int i = 0; i < n; i++) {
names[i]=sc.nextLine().trim();
System.out.printf("current Name is: %s\n", names[i]);
account[i]=0;
}
String tempName;
while((tempName = sc.nextLine()) != null){
System.out.printf("tempName is: %s\n", tempName.trim());
int indexDummy = -1;
for (int j=0; (j< names.length); j++){
if (names[j].equals(tempName)) {
indexDummy = j;
break;
}
}
System.out.printf("indexDummy is: %d\n", indexDummy);
String nextLine = sc.nextLine();
System.out.printf("Next line is: %s\n", nextLine);
StringTokenizer st = new StringTokenizer(nextLine);
int int1 = Integer.parseInt(st.nextToken());
int int2 = Integer.parseInt(st.nextToken());
if(int2 == 0) {
for(int i=0; i<n;i++){
System.out.println(names[i]+" "+account[i]);
}
continue;
}
int quotient = int1/int2;
int tempNum = int2 * quotient;
int remainder = int1-tempNum;
System.out.printf("quotient and remainder are: %d %d\n", quotient, remainder);
account[indexDummy]=account[indexDummy]+remainder-int1;//parsing the two numbers
System.out.println(indexDummy);
System.out.println(names[indexDummy]+" has "+account[indexDummy]);
for (int k=0;k < int2 ;k++){
tempName = sc.nextLine();
for (int j=0; j< names.length; j++){
if (names[j].equals(tempName.trim())) {
//indexDummy2 = j;
account[j] =account[j]+ quotient;
System.out.printf("%s has balance %d\n", names[j], account[j]);
break;
}
} //sort out the output
}
//tempName = sc.next();
}
PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter("gift1.out")));
for(int i=0; i<n;i++){
out.println(names[i]+" "+account[i]);
}
for(int i=0; i<n;i++){
System.out.println(names[i]+" "+account[i]);
}
out.close();
System.exit(0);
}
}