// test client
public static void main(String[] args) {
SparseVector a = new SparseVector(10);
SparseVector b = new SparseVector(10);
a.put(3, 0.50);
a.put(9, 0.75);
a.put(6, 0.11);
a.put(6, 0.00);
b.put(3, 0.60);
b.put(4, 0.90);
StdOut.println("a = " + a);
StdOut.println("b = " + b);
StdOut.println("a dot b = " + a.dot(b));
StdOut.println("a + b = " + a.plus(b));
}
// return the 2-norm
public double norm() {
SparseVector a = this;
return Math.sqrt(a.dot(a));
}
