Issue with C program - c

Question

I have this code:
#include <stdio.h>
#include<conio.h>
main(){
float promAnual=0.0;
int numMeses, numToneladas,i, suma = 0, mesTon = 0;
float toneladas[12];
for(i = 1; i < 13; i++){
printf("Ingrese la cantidad de toneladas del mes #%d->", i);
scanf("%f", &toneladas[i] );
}
for(i = 1; i < 13; i++){
suma = suma + toneladas [i];
}
promAnual = suma / 12.0;
for(i = 1; i < 13; i++){
if(toneladas[i]>promAnual){
numMeses = numMeses + 1;
}
}
numToneladas = 0;
mesTon = 0;
for(i = 1; i < 13; i++){
if(toneladas[i]>toneladas[i+1]){
mesTon = i;
numToneladas = toneladas[i];
}
}
printf("El promedio anual es: %0.2f, %d mes(es) tuvieron mayor cosecha que el promedio anual, y el mayor numero de toneladas se produjo en el mes #%d con %0.2f", promAnual,numMeses,mesTon, numToneladas);
}
The issue is that the last 2 variables in the last printf are showing wrong values, I know why, but I don't know how to fix it, it is because the last "for" is assigning the last value of "i", but I don't know how to fix it.

Answer 1

you would better check the end condition of "for" loop, the array toneladas have 12 stores, which from 0 to 11,but you set it from 1 to 12,maybe it cause your issue.
please try to set "for(i=0;i<12;i++)",and run the code again.

Answer 2

By the looks of the errors in your code, I'd say you're probably not reading a book to learn. That's unfortunate, because people who read books to learn C usually don't have this kind of trouble.
float toneladas[12];
for(i = 1; i < 13; i++){
printf("Ingrese la cantidad de toneladas del mes #%d->", i);
scanf("%f", &toneladas[i] );
}
Here you've declared a carton of 12 eggs, egg[0] through to egg[11] (write them out and count them one by one, and you'll see there are 12)... and then tried to insert into egg[12], which is out of bounds. Expect one smashed egg!
Throughout that code you're referring to that smashed egg again and again. I wouldn't be surprised if the recipe you're concocting is disastrous!
Speaking of smashed eggs, you have an uninitialised variable: int numMesses which you then use without initialisation: numMeses = numMeses + 1;...
int numMeses, numToneladas,i, suma = 0, mesTon = 0;
/* SNIP */
printf("El promedio anual es: %0.2f, %d mes(es) tuvieron mayor cosecha que el promedio anual, y el mayor numero de toneladas se produjo en el mes #%d con %0.2f", promAnual,numMeses,mesTon, numToneladas);
As you can see, numToneladas is declared as int. However, in your call to printf you're telling printf it's a double. You're lying to printf; no wonder it's lying back at you!
You appear to be including the non-portable header <conio.h>, though I see no point. Unlike most, you've not used a single function from that header! Why include a non-portable header you're not using?
My only guess is that you're copy/pasting from somewhere, and attempting to learn by unguided trial and error. As you've seen, that's dangerous; it'll cause you headaches due to strange, difficult to debug bugs like the one you've encountered today. You got lucky this time, because you noticed. If you write code like this in the real world you might cause someone injury!
Read a book! Do the exercises as you stumble across them. I can recommend K&R2E.