我做了一类家庭作业，并正在寻找一些有用的指针，而不是完整的解决方案。 基本上，我必须写一个Java程序，读取文本文件，并通过行列出的信息行，列出行号，最后打印出的最大值和最小值，并且涉及到每个年。 该文本文件包含了一年和当年的温度。 因此，它列出了类似“1900 50.9”。 我并不是要使用数组或扫描仪，这是任务的一部分。 我已经能够成功获得该计划每年和对应的温度一行行与行数打印出来。 有人告诉我，并没有使用while循环。 现在，我唯一的问题是访问的方式文本文件，我可以以某种方式分辨出所有的温度，这是最大的，并且是最小的，而且每一个发生的这一年中，我还没有寻求帮助直到现在因为我希望能够弄明白我自己，但分配不再是值得任何信贷由于后期的处罚。 任何帮助将非常感激，因为我还是想解决这个问题。 谢谢。
这是我有。
public class main {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws Exception {
File temps = new File ("temps.txt"); //Creates path to temps.txt file
FileReader textReader = new FileReader (temps); //Input information from temps.txt file into file reader
BufferedReader kb = new BufferedReader (textReader); //Use buffered reader to hold temps.txt file info from the file reader
String tempList; //Create string variable named tempList
int lineCount = 0; //Create integer variable named lineCount
String sep = ": Temp "; //Create string variable named sep (short for separation) and set it equal to the literal string ":"
String space = " "; //Create string variable named space and set it equal to an actual space between texts
System.out.println("The following is the provided information from the file input. ");
while ((tempList = kb.readLine()) !=null) { //while loop stating that as long as the text file still has values to read (is not null), continue to execute
System.out.println("Line " + lineCount++ + ": Year " + tempList.replace(space, sep)); //Prints out the line number (lineCount++), the info from the temps.txt file with a ":" between the year and the number (tempList.replace (space,sep)
}
}
}
输出迄今是这样的：
Line 0: Year 1900: Temp 50.9
Line 1: Year 1901: Temp 49
Line 2: Year 1902: Temp 49.7
Line 3: Year 1903: Temp 49.5
Line 4: Year 1904: Temp 47.1
Line 5: Year 1905: Temp 49.1
等一路......
Line 99: Year 1999: Temp 52.7
BUILD SUCCESSFUL (total time: 0 seconds)
这里是一个办法做到这一点：
String tempList; //Create string variable named tempList
int lineCount = 0; //Create integer variable named lineCount
String sep = ": Temp "; //Create string variable named sep (short for separation) and set it equal to the literal string ":"
String space = " "; //Create string variable named space and set it equal to an actual space between texts
String maxValueYear = "";
String minValueYear = "";
double maxValue = 0;
double minValue = Double.MAX_VALUE;
System.out.println("The following is the provided information from the file input. ");
while ((tempList = kb.readLine()) !=null) { //while loop stating that as long as the text file still has values to read (is not null), continue to execute
String year = tempList.substring(0, tempList.indexOf(space));
double temp = Double.valueOf(tempList.substring(tempList.indexOf(space), tempList.length()));
if (temp > maxValue) {
maxValue = temp;
maxValueYear = year;
}
if (temp < minValue) {
minValue = temp;
minValueYear = year;
}
System.out.println("Line " + lineCount++ + ": Year " + tempList.replace(space, sep)); //Prints out the line number (lineCount++), the info from the temps.txt file with a ":" between the year and the number (tempList.replace (space,sep)
}
System.out.println("The minimum temp occured in year " + minValueYear + " and was " + minValue);
System.out.println("The maximum temp occured in year " + maxValueYear + " and was " + maxValue);
你需要使用一些变量来跟踪最小和最大温度的。
每次较高（低）温走来更新的变量。
确定具有非常高的最大值和极低分钟外循环开始。
只要你看到内环路A（高）较低的温度，你调整瓦尔。
在循环后您回顾一下。
Highest Seen So Far: -Infinity
(or any really low number so that any number you see next will be higher)
Lowest Seen So Far: Infinity
(or any really high number so that any number you see next will be lower)
Walk through each data point "d":
is d higher than your latest "highest seen so far"?
-> if yes, your new highest seen so far is now d
is d lower than your latest "lowest seen so far"?
-> if yes, your new lowest seen so far is now d
Your highest seen so far is now the highest data point
Your lowest seen so far is now the lowest data point
在伪代码：
highest = -inf
lowest = inf
for d in dataset:
if d > highest:
highest = d
if d < lowest:
lowest = d
print "highest: " + highest
print "lowest: " + lowest
这里有一个例子
假设你的数据集是5 2 8 4
Step 0
Highest: -inf
Lowest: inf
Step 1
See d = 5...that's higher than highest -inf, so new highest is 5.
See d = 5...that's lower than lowest -inf, so new lowest is 5
Highest: 5
Lowest: 5
Step 2:
See d = 2...that's not higher than highest 5...highest is still 5
See d = 2...that is lower than lowest 5...new lowest is 2
Highest: 5
Lowest: 2
Step 3:
See d = 8...that's higher than highest 5...new highest is 8
See d = 8...that's not lower than lowest 2...lowest is still 2
Highest: 8
Lowest: 2
Step 4:
See d = 4...that's not higher than highest 8...highest is still 8
See d = 4...that's not lower than lowest 2...lowest is still 2
Highest: 8
Lowest: 2
Result:
Highest: 8
Lowest: 2
