Summary

#include <stdio.h>

int main(){
    FILE *input = fopen("testdata.in", "r");
    long long data[1005], n=0, sum=0, min=1000005, max=0;
    do{
        if(fscanf(input, "%lld", &data[n])==1){
            min = (data[n]<min?data[n]:min);
            max = (data[n]>max?data[n]:max);
            sum+=data[n++];
        }
    }while(!feof(input));
    fclose(input);
    printf("Count : %lld\n", n);
    printf("Sum   : %lld\n", sum);
    printf("Mean  : %.2f\n", (double)sum/n);
    printf("Min   : %lld\n", min);
    printf("Max   : %lld\n", max);
    printf("Range : %lld\n", max-min);
    return 0;
}