Statistics of an array - c

Question

I need a program to evaluate Min, Max, Avg and Geometric avg of any number of integers. This is what I've come up with so far. Min and Max were working just fine until I added the Avg. Now Min and Avg is working right but Max gives wrong number (usually the second greatest number). Also geometric avg gives only 0.00000. Thanks for your help.
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
int main(int argc, char const *argv[]) {
int arr[100], max, i, min, size, lok = 1;
float arit = 0, geom = 0, sum = 0, prod = 0;
printf("\nSay how many integers you want to input: ");
scanf("%d", &size);
printf("\nType %d integers: ", size);
for (i = 0; i < size; i++) //put values in arr
scanf("%d", &arr[i]);
max = arr[0];
min = arr[0];
for (i = 1; i < size; i++) { //calc maximum
if (arr[i]>max) {
max = arr[i];
lok = i+1;
}
if (arr[i]<min) { //calc minimum
min = arr[i];
lok = i+1;
}
for (i = 0; i < size; i++) { //calc avg
sum = sum + arr[i];
}
arit = sum/size;
for (i = 0; i < size; i++) {
prod = prod * arr[i];
}
geom = pow(prod, 1./size);
}
printf("\n%d is maximum", max);
printf("\n%d is minimum", min);
printf("\n%f is avg", arit);
printf("\n%f is geometric avg", geom);
return 0;
}

Answer 1

The two main problems were
a misplaced closing } brace
wrong intialisation of prod = 0
I have made some other changes too:
check the validity of the inputs
use double instead of float (unless a good reason not to).
remove the unused lok
only one loop is needed for all the statistics
moved the position of the \n newlines as is customary.
This is the amended code:
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
int main(int argc, char const *argv[]) {
int arr[100], max, i, min, size;
double arit = 0, geom = 0, sum = 0, prod = 1; // init prod to 1
printf("\nSay how many integers you want to input: ");
if(scanf("%d", &size) != 1 || size < 1 || size > 100) {
exit(1); // or other action
}
printf("\nType %d integers:\n", size); // added newline
for (i = 0; i < size; i++) {
if(scanf("%d", &arr[i]) != 1) {
exit(1); // or other action
}
}
max = arr[0];
min = arr[0];
for (i = 0; i < size; i++) { // just one loop
if (arr[i] > max) {
max = arr[i];
}
if (arr[i] < min) {
min = arr[i];
}
sum = sum + arr[i];
prod = prod * arr[i];
}
arit = sum / size;
geom = pow(prod, 1.0 / size);
printf("%d is maximum\n", max); // reposition newlines
printf("%d is minimum\n", min);
printf("%f is avg\n", arit);
printf("%f is geometric avg\n", geom);
return 0;
}

Answer 2

This will fix your problem with Min and Max, and I guess also will fix geometric mean(check it) It was a problem closing for sentences
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
int main(int argc, char const *argv[]) {
int arr[100], max, i, min, size, lok = 1;
float arit = 0, geom = 0, sum = 0, prod = 1;
printf("\nSay how many integers you want to input: ");
scanf("%d", &size);
printf("\nType %d integers: ", size);
for (i = 0; i < size; i++) //put values in arr
scanf("%d", &arr[i]);
max = arr[0];
min = arr[0];
for (i = 1; i < size; i++) { //calc maximum
if (arr[i]>max) {
max = arr[i];
lok = i+1;
}
if (arr[i]<min) { //calc minimum
min = arr[i];
lok = i+1;
}
}
for (i = 0; i < size; i++) { //calc avg
sum = sum + arr[i];
}
arit = sum/size;
for (i = 0; i < size; i++) {
prod = prod * arr[i];
}
geom = pow(prod, 1./size);
printf("\n%d is maximum", max);
printf("\n%d is minimum", min);
printf("\n%f is avg", arit);
printf("\n%f is geometric avg", geom);
return 0;
}
About Geometric mean you are doing this.
float arit = 0, geom = 0, sum = 0, prod = 0;
and then
for (i = 0; i < size; i++) {
prod = prod * arr[i];
}
That allways will return 0 because you initialize prod at 0