Reverse a given sentence in Java

Question

Can anyone tell me how to write a Java program to reverse a given sentence?

For example, if the input is:

\"This is an interview question\"

Answer 1

I don't think you should use any library.. 1) Reverse whole string 2) Reverse each word.

public static void revWord(char[] a) {

    // reverse whole
    revWord(a, 0, a.length);

    int st = -1;
    int end = -1;

    for (int i = 0; i < a.length; i++) {

        if (st == -1 && a[i] != ' ') {
            st = i;
        }
        if (end == -1 && a[i] == ' ' ) {
            end = i;
        }
        if(i == a.length-1){
            end=i+1;
        }

        if (st != -1 && end != -1) {
            revWord(a, st, end );

            st = -1;
            end = -1;
        }

    }

}

public static void revWord(char[] a, int s, int l) {
    int mid = (l - s) / 2;
    l--;

    for (int i = 0; i < mid; i++, l--) {
        char t = a[s+i];
        a[s+i] = a[l];
        a[l] = t;
    }
}

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