You have:

for(int i=1;i<=m;i++){
    while(b[i]!=i){
        swa(i,b[i],m,q);
        int t=b[i];
        swap(b[i],b[t]);
    }
}

For $$$i > 2002$$$, there's some garbage at b[i] and b[t] = b[b[i]], so b[i] != i will almost certainly be true.

So, the while loop runs indefinitely, and swa() appends to q $$$3$$$ times, which leads to MLE.