RTE (SIGSEGV: segmentation fault, probably incorrect memory access)

#include<stdio.h>
#include<algorithm>

using namespace std;

int n, c, k, m, cnt, flag;
int it[501], ct[501], arr[501];

struct chek{

    int i;
    int arr;
    int lis;
    long long cnt;

    inline bool operator < (const chek &tmp) const{
        return lis > tmp.lis || (lis == tmp.lis && arr < tmp.arr);
    }
} chek[501];

void its(int t, int s, int e){

    if(flag == 1) return;
    m = (s + e) / 2;
    if(it[m] == t || s == e){flag = 1; return;}
    else if(it[m] < t) its(t, m + 1, e);
    else if(it[m] > t) its(t, s, m);

}

void lis(int x){

    int i;

    flag = 0; it[1] = ct[1]; cnt = 1;
    for(i = 2; i <= x; i++){
        if(it[cnt] < ct[i]) m = ++cnt;
        else{
            flag = 0;
            its(ct[i], 1, cnt);
        }
        if(m > 1)
            it[m] = ct[i];
    }
}

int main(void){

    //freopen("input.txt", "r", stdin);
    //freopen("output.txt", "w", stdout);

    int i, j, l, chek2;
    long long chek3, chek4;
    long long tmp;
    scanf("%d", &c);
    for(l = 1; l <= c; l++){
        scanf("%d %d", &n, &k);
        for(i = 1; i <= n; i++){
            scanf("%d", &chek[i].arr);
            ct[i] = chek[i].arr;
            chek[i].i = i;
        }
        for(i = 1; i <= n; i++){
            lis(n - i + 1);
            chek[i].lis = cnt;
            for(j = 2; j <= n - i + 1; j++){
                ct[j - 1] = ct[j];
            }
        }
        for(i = n; i > 0; i--){
            for(j = n; j > i; j--){
                if(chek[j].arr > chek[i].arr && chek[j].lis == chek[i].lis - 1){
                    chek[i].cnt += chek[j].cnt;
                }
            }
            if(chek[i].cnt == 0) chek[i].cnt = 1;
        }
        sort(chek + 1, chek + n + 1);
        printf("%d\n", chek[1].lis);
        cnt = 1; chek2 = 0; chek3 = 0;
        for(i = chek[1].lis; i > 0; i--){
            tmp = 0; chek4 = 0;
            while(tmp < k){
                if(chek2 < chek[cnt].arr && chek[cnt].lis == i && chek[cnt].i > chek3){
                    k -= chek4;
                    chek4 = chek[cnt].cnt;
                    tmp += chek[cnt].cnt;
                    chek2 = chek[cnt].arr;
                }
                cnt++;
            }
            printf("%d ", chek2);
        }
        printf("\n");
        for(j = 1; j <= n; j++){
            chek[j].arr = 0;
            chek[j].lis = 0;
            chek[j].cnt = 0;
            chek[j].i = 0;
        }
    }
    return 0;
}