Intersection Point in Y Shaped Linked Lists | GFG POTD | 13-11-24 | Medium | GFG Problem of the day

[@codewithuday]

class Solution {
public:
// Function to find intersection point in Y shaped Linked Lists.
// length function
int getLen(Node* head){
int len = 0 ;
while(head){ len++; head= head->next;}
return len;
}
// head1 -> longest , head2 =smallest;
int getIntersectionPoint(int diff,Node* head1,Node* head2){
for(int i = 0 ;inext;
}
while(head1 && head2){
if(head1 == head2) return head1->data;
head1= head1->next;
head2= head2->next;
}
return -1;
}
int intersectPoint(Node* head1, Node* head2) {
// O(m+n) | O(1)
int n1 = getLen(head1) ;
int n2 = getLen(head2);
int diff =0;
if(n1 > n2){
diff = n1 - n2;
return getIntersectionPoint(diff,head1,head2);
}
diff = n2 - n1;
return getIntersectionPoint(diff,head2,head1);
}
};

[@codewithuday]

class Solution {
public:
// Function to find intersection point in Y shaped Linked Lists.
int intersectPoint(Node* head1, Node* head2) {
// Your Code Here
// 2nd Approach
// O(m+n) | O(m+n)
unordered_map map;
while(head1){
map[head1] = 1;
head1 = head1->next;
}
while(head2){
if(map[head2]) return head2->data;
head2 = head2->next;
}
return -1;
}
};