Create a Pull Request in 'GeeksforGeeks VIT Bhopal'-pharshithachowdary-Vrunique

class Solution {
public:
ListNode* addTwoNumbers(ListNode* l1, ListNode* l2) {
int sum=0;
ListNode *l3=NULL;
ListNode **node=&l3;
while(l1!=NULL||l2!=NULL||sum>0)
{
if(l1!=NULL)
{
sum+=l1->val;
l1=l1->next;
}
if(l2!=NULL)
{
sum+=l2->val;
l2=l2->next;
}
(*node)=new ListNode(sum%10);
sum/=10;
node=&((*node)->next);
}
return l3;
}
};
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class Solution {
public:
int lengthOfLongestSubstring(string s) {
if(s.length() == 0) return 0;
int map[256] = {0};
int n = s.length();
int start = 0;
int max_len = INT_MIN;
for(int i=0;i<n;++i){
map[s[i]]++;
if(map[s[i]] > 1){
max_len = max(max_len, (i - start));
while(s[start] != s[i]){
map[s[start]]--;
start++;
}
map[s[start]]--;
start++;
}
}
max_len = max(max_len, (n - start));
if(start == 0) return n;
else return max_len;
}
};
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class Solution {
public:
string longestPalindrome(string s) {
int len = s.length();
vector<vector<bool>> mem(len, vector<bool>(len, false));
int best_start = 0;
int best_len = 1;
for(int i = 0; i<len; i++) mem[i][i]=true;
for(int l = 2; l<=len; l++)
for(int start = 0; start<=len-l; start++)
{
int end = start+l-1;
if ((s[start]==s[end]) && (l==2 ||mem[start+1][end-1]))
{
mem[start][end] = true;
best_start=start;
best_len=l;
}
}
return s.substr(best_start,best_len);
}
};
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class Solution {
public:
int myAtoi(string str) {
int i = 0;
int sign = 1;
int result = 0;
if (str.length() == 0) return 0;



//Discard whitespaces in the beginning
while (i < str.length() && str[i] == ' ')
i++;



// Check if optional sign if it exists
if (i < str.length() && (str[i] == '+' || str[i] == '-'))
sign = (str[i++] == '-') ? -1 : 1;



// Build the result and check for overflow/underflow condition
while (i < str.length() && str[i] >= '0' && str[i] <= '9') {
if (result > INT_MAX / 10 ||
(result == INT_MAX / 10 && str[i] - '0' > INT_MAX % 10)) {
return (sign == 1) ? INT_MAX : INT_MIN;
}
result = result * 10 + (str[i++] - '0');
}
return result * sign;
}
};

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class Solution {
public:
ListNode* addTwoNumbers(ListNode* l1, ListNode* l2) {
int sum=0;
ListNode *l3=NULL;
ListNode **node=&l3;
while(l1!=NULL||l2!=NULL||sum>0)
{
if(l1!=NULL)
{
sum+=l1->val;
l1=l1->next;
}
if(l2!=NULL)
{
sum+=l2->val;
l2=l2->next;
}
(*node)=new ListNode(sum%10);
sum/=10;
node=&((*node)->next);
}
return l3;
}
};