Print All Binary

Print All Binary from 0 to n-1
e.g. Given 10, print all binary number from 0 to 10-1

/**
    * print all binary from zero to num-1 with length log2(num)
    * @param num maximum number 
    */
    public static void printAllBinary(int num) {
        String str = "";
        int binLen = (int)Math.ceil(Math.log(num)/Math.log(2));

        for(int j=0; j<num; j++){
            int n = j;
            for(int i=0; i<binLen; i++){
                if(n % 2 == 0)
                    str = "0" + str;
                else
                    str = "1" + str;

                n = n/2;
            } 
            Print.plb(str);
            str = "";
        } 
    }

Source Code

Print Excel Header Number
e.g. Given 10, output:
A->1
B->2
C->3
D->4
E->5
F->6
G->7
H->8
I->9
G->10

// [1 -> 26] = ['A' -> 'Z']
    // [0 -> 25]   ['A' -> 'Z'] 
    public static void excelNumSaveLength(int num) {
        int binLen = 1;
        if(num == 1) 
            binLen = 1;
        else 
            binLen = (int)Math.ceil(Math.log(num)/Math.log(26));

        for(int j=1; j<=num; j++){
            int n = j;
            String str = "";
            for(int i=1; i<=binLen; i++){
                String s = Aron.intToAlphabetUpper((n-1)%26);
                str = s + str;
                n = (n-1)/26;
            } 
            Print.plb(str);
        } 
    }

Print all Excel Header Number from A to ...

// [1 -> 26] = ['A' -> 'Z']
    // [0 -> 25]   ['A' -> 'Z'] 
    public static void printExcel(int num){
        int base = 26;
        for(int i=1; i<=num; i++){
            int x = i;
            String str = "";
            if(x-1 == 0)
                str = 'A' + str;
            else{
                while( x > 0){
                    int r = (x-1) % base;
                    String s = Aron.intToAlphabetUpper(r);
                    str = s + str;
                    x = (x-1) / base;
                }
            }
            Print.plb(str);
        }
    }

Source Code