# Constructor of a Struct in C++ Causes Non-Zero Exit Code

When I call the constructor for my SegTree struct in the code below, I keep getting a non-zero exit code. Can someone explain why this is happening and how to fix my code?

``````#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <algorithm>
#include <string>
#include <vector>
#include <string.h>

using namespace std;

struct SegTree{
int N;
long long tree [1<<20], arr [1<<20];
SegTree(int x){ N = x; }
int left(int p){ return p<<1; }
int right(int p){ return (p<<1) + 1; }
void build(int p, int L, int R, bool isOR){
if(L == R) tree[p] = arr[L];
else{
build(left(p), L, (L+R)/2, !isOR); build(right(p), (L+R)/2+1, R, !isOR);
if(isOR) tree[p] = tree[left(p)] | tree[right(p)];
else tree[p] = tree[left(p)] ^ tree[right(p)];
}
}
void update(int p, int L, int R, bool isOR, int place, long long val){
if(L > R || L > place || R < place) return;
if(L == R && L == place){
tree[p] = val;
return;
}
update(left(p), L, (L+R)/2, !isOR, place, val); update(right(p), (L+R)/2+1, R, !isOR, place, val);
if(isOR) tree[p] = tree[left(p)] | tree[right(p)];
else tree[p] = tree[left(p)] ^ tree[right(p)];
}
};

int len, numQueries;
bool start;

int main(){
scanf("%d %d", &len, &numQueries); start = len%2 == 1;
SegTree st(len);
/*for(int i = 1; i <= len; i++){
long long temp; scanf("%d", &temp);
st.arr[i] = temp;
}
st.build(1, 1, len, start);
for(int i = 0; i < numQueries; i++){
int x; long long y; scanf("%d %d", &x, &y);
st.update(1, 1, len, start, x, y);
cout << st.tree[1] << endl;
}*/
return 0;
}
``````

Thanks,
``````long long *tree, *arr;