Function main

code/Chapter2/2-2.c:7–21

int a[N],b[N],c[N];
int i;
int main(){
        for(i= 0; i <N; i++){
                a[i]=i+ 1;
                b[i]=i+2;
                c[i]=i+3;
}
        struct  timeval start,end;
        gettimeofday(&start,NULL);
        for (i=0; i<N;i++)
                c[i]=c[i]+a[i]*b[i];
        gettimeofday(&end,NULL);
        double timeuse=(end.tv_sec-start.tv_sec)+(end.tv_usec-start.tv_usec)/1000000.0;
        printf("time=%f\n",timeuse);
        return 0;
}