#include <stdio.h>
#include <stdlib.h>
#include <math.h>

int main(int argc, char *argv[]) {
  int i;
  double t;
  double sum = 0.0;

  // check to see if there is at least one argument
  if( argc < 2 ) {
    printf("Usage: %s <number> ...\n", argv[0]);
    printf("  prints out the square root of the sum of squares of the numbers listed\n");

    // exit with an error (non-zero value)
    exit(-1);
  }
  
  // loop over the arguments on the command line
  printf("\nVector: ( ");
  for(i=1;i<argc;i++) {
    
    // read in the number and convert it to a floating point value
    t = atof(argv[i]);
    printf("%.2f ", t);

    // add the square to the sum
    sum += t*t;
    
  }
  printf(")\n");

  // print out the square root
  printf("\nThe length of the vector is %.4f\n\n", sqrt( sum ));

  // return normal execution
  return(0);

}