The output for average is not correct - c

Question

The average which is the last output should display 60 but I got it wrong. What is the error here? Here is the temperature input 72, 46, 90, 20, 70 85, 60, 40, -1000.
The total hot days should display 2 but on the output I got 3.
#include <stdio.h>
int categorize_days(int temp);
int categorize_days(int temp){
if (temp >= 85){
return 1;
}
else if(temp >=60){
return 2;
}
else{
return 3;
}
}
int main(){
int i, temp, h, p,c, temp_ave=0, type_days;
double ave;
printf("Lets check the whether !\n");
printf("Keep entering the integer temperature, enter -1000 to quit\n\n");
printf("Temperature: ");
scanf("%d", &temp);
while(temp!= -1000){
for(i = 0; i<8; i++ ){
temp_ave =+ temp;
}
type_days = categorize_days(temp);
if( type_days == 1){
printf ("Day: h\n\n");
h++;
}
else if(type_days == 2){
printf ("Day: p\n\n");
p++;
}
else{
printf ("Day: c\n\n");
c++;
}
printf("Temperature: ");
scanf("%d", &temp);
}
printf("End\n\n");
ave = temp_ave/8;
printf("Total Hot days: %d \n", h);
printf("Total Pleasant days: %d \n", p);
printf("Total Cold days: %d \n", c);
printf("Average temperature for 8 days is %f", ave);
}

Answer 1

The first big mistake is here:
for(i = 0; i<8; i++ ){
temp_ave =+ temp; // You are not adding temp to temp_ave, to add you should
} // write temp_ave += temp;
// Anyway this won't help you, cause you are trying to add the same number 8 times.
// So therefore it will give you wrong average, when you are calculating it.
I think this is what you wanted to do.
#include <stdio.h>
int categorize_days(int temp) {
return (temp >= 85 ? 1 : (temp >= 60 ? 2 : 3));
}
int main() {
int temp = 0, h = 0, p = 0, c = 0, cnt = -1;
double ave = 0;
printf("Lets check the whether !\n");
printf("Keep entering the integer temperature, enter -1000 to quit\n\n");
while (temp != -1000) {
ave += temp;
cnt ++;
printf("Temperature: ");
scanf("%d", &temp);
int type_days = categorize_days(temp);
if (type_days == 1) {
printf ("Day: h\n\n");
h++;
}
else if(type_days == 2) {
printf ("Day: p\n\n");
p++;
}
else {
printf ("Day: c\n\n");
c++;
}
}
printf ("End\n\n");
printf ("Total Hot days: %d \n", h);
printf ("Total Pleasant days: %d \n", p);
printf ("Total Cold days: %d \n", c);
printf ("Average temperature for 8 days is %f", ave / cnt);
}

Answer 2

Don't use magic numbers in the code, following and updating becomes tedious. Use #define macros as necessary.
#define HOT_CUTOFF 85 // Fahrenheit
#define COLD_CUTOFF 60 // Fahrenheit
#define INPUT_GUARD -1000
Make use of enum to list out day-types:
enum {
eHotDay = 1,
eColdDay = 2,
eCozyDay = 3
} eDayType;
Then your day_type() would change to :
int day_type (const int temp) {
if (temp >= HOT_CUTOFF)
return eHotDay;
else if (temp <= COLD_CUTOFF) // should be less than or equal to
return eColdDay;
else
return eCozyDay;
}
Always initialise variables before usage. h, p & c are being used without initialisation. Also, temp_ave is misleading name for keeping total.
int i, temp, h, p,c, temp_ave=0, type_days;
Why limit only to 8 inputs when you've -1000 as guard?
Simplified:
#include <stdio.h>
#define HOT_CUTOFF 85 // Fahrenheit
#define COLD_CUTOFF 60 // Fahrenheit
enum {
eHotDay = 1,
eColdDay = 2,
eCozyDay = 3
} eDayType;
//int categorize_days (int temp); // redundant as you're defining the function before usage
//int categorize_days (int temp) {
int day_type (const int temp) {
if (temp >= HOT_CUTOFF)
return eHotDay;
else if (temp <= COLD_CUTOFF) // should be less than or equal to
return eColdDay;
else
return eCozyDay;
}
int main() {
printf ("Keep entering the integer temperature, enter -1000 to quit\n\n");
int total = 0;
int count = 0;
int hot = 0, cold = 0, cozy = 0;
while (1) {
int temp;
if (1 != scanf ("%d", &temp)) {
printf ("ERROR: Invalid input\n");
return 1;
}
if (INPUT_GUARD == temp) break;
total += temp;
++count;
switch (day_type(temp)) {
case eHotDay : ++hot; break;
case eColdDay : ++cold; break;
case eCozyDay : ++cozy; break;
}
}
double avgTemp = 0.0;
if (count)
avgTemp = (double)total / count;
printf ("End\n\n");
printf ("Total Hot days: %d \n", hot);
printf ("Total Pleasant days: %d \n", cozy);
printf ("Total Cold days: %d \n", cold);
printf ("Average temperature for 8 days is %.2lf\n", avgTemp);
return 0;
}

Answer 3

The average which is the last output should display 60 but I got it wrong.
This loop is a mess. Same as temp_ave = +temp;, same as temp_ave = temp;.
for (i = 0; i<8; i++) {
temp_ave =+ temp; // ????????
}
Instead:
temp_ave += temp; // Note +=
temp_ave/8 in an int division. Instead, perform the division per the type of ave avoiding casts.
// ave = temp_ave/8;
ave = temp_ave;
ave /= 8; // Division done per wider of type of `ave` and `int` constant `8`.
The total hot days should display 2 but on the output I got 3.
Enable all warnings.
Initialize h, p, c. #Weather Vane