$ cat summation1.c
Result:
#include<stdio.h>
#include<stdlib.h>
int main(int argc, char* argv[]){
if(argc!=2){
printf("Bad argument\n");
exit(1);
}
long int a=0;
for (long int i=1; i<=atoi(argv[1]); i++){
a+=i;
}
printf("%ld\n",a);
return 0;
}
Command:
$ cat summation2.c
Result:
#include<stdio.h>
#include<stdlib.h>
int main(int argc, char* argv[]){
if (argc != 2){
printf("Bad argument\n");
exit(1);
}
long int a = 0;
long int n = atoi(argv[1]);
a = (n*(n+1))/2;
printf("%ld\n", a);
return 0;
}
Command:
$ gcc -o summation1 summation1.c
$ gcc -o summation2 summation2.c
$ time ./summation1 100000000
Result:
5000000050000000
real 0m3.517s
user 0m3.511s
sys 0m0.002s
Command:
$ time ./summation2 100000000
Result:
5000000050000000
real 0m0.005s
user 0m0.001s
sys 0m0.001s
