60 lines
1.6 KiB
Java
60 lines
1.6 KiB
Java
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import java.io.BufferedReader;
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import java.io.InputStreamReader;
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/**
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*
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* @author Varun Upadhyay (https://github.com/varunu28)
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*
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*/
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// Driver program
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public class AnyBaseToDecimal {
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public static void main (String[] args) throws Exception{
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BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
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String inp = br.readLine();
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int base = Integer.parseInt(br.readLine());
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System.out.println("Input in base " + base + " is: " + inp);
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System.out.println("Decimal value of " + inp + " is: " + convertToDecimal(inp, base));
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br.close();
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}
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/**
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* This method produces a decimal value of any given input number of any base
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* @param inp_num String of which we need the decimal value and base in integer format
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* @return string format of the decimal value
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*/
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public static String convertToDecimal(String inp_num, int base) {
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int len = inp_num.length();
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int num = 0;
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int pow = 1;
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for (int i=len-1; i>=0; i--) {
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if (valOfChar(inp_num.charAt(i)) >= base) {
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return "Invalid Number";
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}
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num += valOfChar(inp_num.charAt(i))*pow;
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pow *= base;
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}
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return String.valueOf(num);
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}
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/**
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* This method produces integer value of the input character and returns it
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* @param c Char of which we need the integer value of
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* @return integer value of input char
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*/
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public static int valOfChar(char c) {
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if (c >= '0' && c <= '9') {
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return (int)c - '0';
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}
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else {
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return (int)c - 'A' + 10;
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}
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}
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}
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