POJ 1396 Simple Arithmetics
这是一道大数模拟题，所以就想用Java来写写。于是各种TLE。
无奈就研究怎样才不会TLE。
注解一下关于Java的文件操作：
1、正常的输入输出（效率不高）
import java.util.Scanner;
import java.io.*;
public class Main {
static private final String INPUT = "data1.in";
static private final String OUTPUT = "1.out";
public static void main(String[] args) {
FileInputStream instream = null; //建立文件输入对象
PrintStream outstream = null; //建立屏幕输出对象
try {
instream = new FileInputStream(INPUT); //初始化文件输入对象
outstream = new PrintStream(new FileOutputStream(OUTPUT)); //初始化屏幕输出对象输出到文件
System.setIn(instream);
System.setOut(outstream);
} catch (Exception e) {
System.err.println("Error Occurred."); //如果访问文件有异常就输出并退出
}
Scanner cin = new Scanner(System.in);
while (cin.hasNext()) { //判断是否到文件结尾
String s = cin.next(); //输入输出
System.out.println(s);
}
}
}
2、Buffer输入输出（效率高）：
import java.io.*;
public class Main {
static private final String INPUT = "data1.in";
static private final String OUTPUT = "1.out";
public static void main(String[] args) throws IOException {
BufferedReader read = null; //建立文件输入对象
PrintStream outstream = null; //建立屏幕输出对象
try {
read = new BufferedReader(new FileReader(INPUT));
outstream = new PrintStream(new FileOutputStream(OUTPUT)); //初始化屏幕输出对象输出到文件
System.setOut(outstream);
} catch (Exception e) {
System.err.println("Error Occurred."); //如果访问文件有异常就输出并退出
}
StringBuffer s = new StringBuffer(""); //StringBuffer初始化
String string;
while (null != (string = read.readLine())) { //读取数据时每次读一行
s.append(string); //加入到 StringBuffer 里面
s.append("\n"); //格式化输出每一行都要有回车
}
System.out.println(s);//整体输出StringBuffer
}
}
就有了下面的AC代码：
import java.math.BigInteger;
import java.util.Scanner;
import java.io.*;
import javax.jws.soap.SOAPBinding;
public class Main {
static private final String INPUT = "data1.in";
static private final String OUTPUT = "1.out";
public static void main(String[] args) throws IOException {
FileInputStream instream = null;
PrintStream outstream = null;
/*try {
instream = new FileInputStream(INPUT);
outstream = new PrintStream(new FileOutputStream(OUTPUT));
System.setIn(instream);
System.setOut(outstream);
} catch (Exception e) {
System.err.println("Error Occurred.");
}*/
int i, j, t;
char cc = 0;
BigInteger a = BigInteger.ZERO;
BigInteger b = BigInteger.ZERO;
BigInteger c = BigInteger.ZERO;
//Scanner cin = new Scanner(System.in);
BufferedReader read = new BufferedReader(new InputStreamReader(System.in));
//BufferedReader read = new BufferedReader(new FileReader(INPUT));
//String s = cin.next();
//System.out.println(s);
t = Integer.valueOf(read.readLine());
while (t--!=0) {
StringBuffer s0 = new StringBuffer();
String str = read.readLine();
String tmp;
for (i = 0; i <= str.length(); i++) {
if (str.charAt(i) == '+' || str.charAt(i) == '*'
|| str.charAt(i) == '-') {
cc = str.charAt(i);
break;
}
}
if (cc == '+') {
String[] strs = str.split("\\+");
a = new BigInteger(strs[0]);
b = new BigInteger(strs[1]);
c = a.add(b);
Integer min = 0;
tmp = String.valueOf(c);
if (min < tmp.length()) {
min = tmp.length();
}
if (min < strs[0].length()) {
min = strs[0].length();
}
if (min < strs[1].length() + 1) {
min = strs[1].length() + 1;
}
for (i = 0; i < min - strs[0].length(); i++) {
//s0.append(" ");
s0.append(" ");
}
//System.out.println(strs[0]);
s0.append(strs[0]);
s0.append("\n");
for (i = 0; i < min - strs[1].length() - 1; i++) {
//s0.append(" ");
s0.append(" ");
}
//System.out.println("+" + strs[1]);
s0.append("+");
s0.append(strs[1]);
s0.append("\n");
for (i = 0; i < min; i++) {
//s0.append("-");
s0.append("-");
}
//System.out.println();
s0.append("\n");
for (i = 0; i < min - tmp.length(); i++) {
s0.append(" ");
}
//System.out.println(tmp);
s0.append(tmp);
s0.append("\n");
} else if (cc == '-') {
String[] strs = str.split("\\-");
a = new BigInteger(strs[0]);
b = new BigInteger(strs[1]);
c = a.subtract(b);
Integer min = 0;
Integer min2=strs[1].length()+1;
tmp = String.valueOf(c);
if(min2<tmp.length())
{
min2=tmp.length();
}
if (min < tmp.length()) {
min = tmp.length();
}
if (min < strs[0].length()) {
min = strs[0].length();
}
if (min < strs[1].length() + 1) {
min = strs[1].length() + 1;
}
for (i = 0; i < min - strs[0].length(); i++) {
s0.append(" ");
}
//System.out.println(strs[0]);
s0.append(strs[0]);
s0.append("\n");
for (i = 0; i < min - strs[1].length() - 1; i++) {
s0.append(" ");
}
//System.out.println("-" + strs[1]);
s0.append("-");
s0.append(strs[1]);
s0.append("\n");
for(i=0;i<min-min2;i++)
{
s0.append(" ");
}
for (i = 0; i < min2; i++) {
s0.append("-");
}
//System.out.println();
s0.append("\n");
for (i = 0; i < min - tmp.length(); i++) {
s0.append(" ");
}
//System.out.println(tmp);
s0.append(tmp);
s0.append("\n");
} else if (cc == '*') {
String[] strs = str.split("\\*");
a = new BigInteger(strs[0]);
b = new BigInteger(strs[1]);
c = a.multiply(b);
Integer min = 0;
tmp = String.valueOf(c);
int len = tmp.length();
if(len<strs[1].length()+1)
{
len=strs[1].length()+1;
}
min=strs[1].length()+1;
for (i = 0; i < len - strs[0].length(); i++) {
s0.append(" ");
}
//System.out.println(strs[0]);
s0.append(strs[0]);
s0.append("\n");
for (i = 0; i < len - strs[1].length() - 1; i++) {
s0.append(" ");
}
//System.out.println("*" + strs[1]);
s0.append("*");
s0.append(strs[1]);
s0.append("\n");
if (strs[1].length() != 1) {
if (len < min)
len = min;
int le2 = strs[1].length();
BigInteger d = BigInteger.ZERO;
for (i = 0; i < le2; i++) {
d = BigInteger.valueOf(Long.valueOf(String
.valueOf(strs[1].charAt(le2 - 1 - i))));
d = d.multiply(a);
String tmp2 = String.valueOf(d);
if(i==0)
{
if(min<tmp2.length())
{
min=tmp2.length();
}
for (j = 0; j < len - min; j++) {
s0.append(" ");
}
for (j = 0; j < min; j++) {
s0.append("-");
}
// System.out.println();
s0.append("\n");
}
for (j = 0; j < len - tmp2.length() - i; j++) {
s0.append(" ");
}
//System.out.println(tmp2);
s0.append(tmp2);
s0.append("\n");
}
for (i = 0; i < len - tmp.length(); i++) {
s0.append(" ");
}
for (i = 0; i < tmp.length(); i++) {
//System.out.printf("-");
s0.append("-");
}
//System.out.println();
s0.append("\n");
}
else
{
int min2=tmp.length();
if(min2<strs[1].length()+1)
{
min2=strs[1].length()+1;
}
for (i = 0; i < len - min2; i++) {
s0.append(" ");
}
for (i = 0; i < min2; i++) {
//System.out.printf("-");
s0.append("-");
}
//System.out.println();
s0.append("\n");
}
for (i = 0; i < len - tmp.length(); i++) {
s0.append(" ");
}
//System.out.println(c);
s0.append(c);
s0.append("\n");
}
//if(t-1!=0)System.out.println();
System.out.println(s0);
//System.out.println("\r");
}
//}
}
}
