Solving #1015 (Brush) in LightOJ - c

Question

I am trying to solve the following problem.
Input
Input starts with an integer T (≤ 100), denoting the number of test cases.
Each case starts with a blank line. The next line contains an integer N (1 ≤ N ≤ 1000), means that there are N students. The next line will contain N integers separated by spaces which denote the dust unit for all students. The dust unit for any student will not contain more than two digits.
Output
For each case print the case number and the total required dust units.
Sample Input
+--------------+-------------------------+
| Sample Input | Output for Sample Input |
+--------------+-------------------------+
| 2 | Case 1: 16 |
| | Case 2: 100 |
| 3 | |
| 1 5 10 | |
| | |
| 2 | |
| 1 99 | |
+--------------+-------------------------+
Here is my code:
#include <stdio.h>
int main() {
int kase = 0;
int i = 0, j = 0;
do {
scanf("%d", &kase);
} while (kase > 100);
int group[kase];
int tdust[kase];
for (i = 1; i <= kase; i++) {
tdust[i] = 0;
printf("\n");
do {
scanf("%d", &group[i]);
} while (group[i] < 1 || group[i] > 1000);
int stdNumber[group[i]];
for (j = 1; j <= group[i]; j++) {
do {
scanf("%d", &stdNumber[j]);
} while (stdNumber[j] >= 100);
tdust[i] = tdust[i] + stdNumber[j];
}
}
for (i = 1; i <= kase; i++)
printf("\nCase %d: %d", i, tdust[i]);
}
When I submit my code, OnlineJudge says I've got the wrong answer. How can I fix it?

Answer 1

You are getting WA because your code exhibits UB(Undefined Behaviour). You assume that the valid indices for an array of length n where n is a natural number, starts from 1 and ends at n. That is wrong.For an array of length n(n is a natural number), Array indices start from 0 and end at n-1.
To fix it, change
for(i=1; i<=kase; i++)
To
for(i=0; i<kase; i++)
And similarly,do the same for all the other loops. Also change
printf("\nCase %d: %d",i,tdust[i]);
To
printf("\nCase %d: %d",i+1,tdust[i]);
So that you get the desired result.