segment tree based

[abhilasha1]

  #include<iostream>
 #define MAX 1000000
    #define loop0(i,j) for(int i=0;i<j;i++)
    #define loop1(i,j) for(int i=1;i<j;i++)

    using namespace std;

    bool flag[MAX]={0};
    int tree[MAX]={0};
void update(long int node,long int b,long int e,long int i,long int j)
{
    if(b>j || e<i) return;

    if(b>=i && e<=j)
    {
        if(flag[node])
        {
            flag[node]=0;
            return;
        }
        else
        {
            tree[node]=e-b+1-tree[node];
            flag[2*node]=!flag[2*node];
            flag[2*node+1]=!flag[2*node+1];

            return;
        }
    }
     else
    {
        if(flag[node])
        {
            flag[node]=0;

            flag[2*node]=1;
            flag[2*node+1]=1;

        }
        update(2*node,b,(b+e)/2,i,j);
        update(2*node+1,(b+e)/2+1,e,i,j);
        tree[node]=tree[2*node]+tree[2*node+1];
        return;
    }
}
long int query(long int node,long int b,long int e,long int i,long int j)
{
    long int l,r;

    if(b>j || e<i) return -1;

    if(b>=i && e<=j)
    {
        if(!flag[node])
         return tree[node];
        else
        {
            flag[node]=0;

            tree[node]=e-b+1-tree[node];

            flag[2*node]=!flag[2*node];
            flag[2*node+1]=!flag[2*node+1];

            return tree[node];
        }
    }
    else
    {
        if(flag[node])
        {
            flag[node]=0;
             tree[node]=e-b+1-tree[node];
             flag[2*node]=!flag[2*node];
            flag[2*node+1]=!flag[2*node+1];
            l=query(2*node,b,(b+e)/2,i,j);
        r=query(2*node+1,(b+e)/2+1,e,i,j);
        if(l==-1&r==-1)
        return tree[node];
        else if(l==-1) return tree[node]=r;
        else if(r==-1) return tree[node]=l;
        return tree[node]=(l+r);
        }
        l=query(2*node,b,(b+e)/2,i,j);
        r=query(2*node+1,(b+e)/2+1,e,i,j);
        if(l==-1&r==-1)
        return tree[node];
        else if(l==-1) return r;
        else if(r==-1) return l;
        return (l+r);



    }
}
 int main()
    {
           int k, t, tests, m, n;
           int f, a, b, z;
           int i;
           for(i=0;i<MAX;i++)
           {
                             tree[i]=0;
                             flag[i]=0;
                             }
           scanf("%d %d",&tests,&m);
           loop0(i, m)
           {
               scanf("%d %d %d",&f,&a,&b);
             if(f==0)
                   update(1,0,tests-1,a,b);
               else
                   printf("%d\n",query(1,0,tests-1,a,b));
           }
           return 0;
    }

[abhilasha1]

please help with it as it gives wrong answer for code chef flipping coin problem