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资源说明：Our own partial implementation of the Java's Scanner
# Java's Scanner : our implementation
On France-IOI, we are using the gcj compiler to compile Java's source codes into executables.
We have our own implementation of the Java's Scanner.
* It fixes speed and memory usage problems (see below).
* It fixes some gcj's Scanner "bugs" (see below)
* It hasn't all the original functions
## Example of use
Exactly as you would use the original Java's Scanner :
Scanner sc = new Scanner(System.in);
int val = sc.nextInt()
## Supported functions
Original functions :
public boolean hasNext();
public String next();
public String nextLine();
public int nextInt();
public long nextLong();
public float nextFloat();
public double nextDouble();
Added functions :
public char nextChar();
## Bugs fixed
Using `nextDouble()` to read the value `0` raises the error `ava.util.InputMismatchException: "0" is not a double`.
See http://stackoverflow.com/questions/9055788/java-scanner-0-is-not-a-double for more details.
Our Scanner fixes that
## Speed and memory usage
For this benchmark we are reading `N` integers on standard input, the most common usage in algorithmic contests.
Comparison of Java's Scanner / our Scanner
For 10 integers :
Time : .07s vs .07s
Memory : 25164K vs 20760K
Ratios (time/mem) : 1.0 and 1.2
For 5000 integers :
Time : .26s vs .08s
Memory : 30036K vs 21596K
Ratios (time/mem) : 3.2 and 1.3
For 10000 integers :
Time : .44s vs .06s
Memory : 30956K vs 22380K
Ratios (time/mem) : 7.3 and 1.3
For 25000 integers :
Time : 1.02s vs .07s
Memory : 34464K vs 23704K
Ratios (time/mem) : 14.5 and 1.4
For 50000 integers :
Time : 1.97s vs .11s
Memory : 39596K vs 25788K
Ratios (time/mem) : 17.9 and 1.5
For 75000 integers :
Time : 2.93s vs .20s
Memory : 44988K vs 26060K
Ratios (time/mem) : 14.6 and 1.7
For 100000 integers :
Time : 3.85s vs .23s
Memory : 50456K vs 26056K
Ratios (time/mem) : 16.7 and 1.9
For 150000 integers :
Time : 5.68s vs .27s
Memory : 60648K vs 26060K
Ratios (time/mem) : 21.0 and 2.3
For 200000 integers :
Time : 6.86s vs .37s
Memory : 75148K vs 26320K
Ratios (time/mem) : 18.5 and 2.8
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