leetcode

Solution to some Leetcode problems written in C++
git clone git://git.dimitrijedobrota.com/leetcode.git
Log | Files | Refs | README | LICENSE
commitfcbe5a5631c5a8bd65ff903744f1595198996e66
parent6ab4ab94636345f07aaacb244206eeb80aef0efa
authorDimitrije Dobrota <mail@dimitrijedobrota.com>
dateMon, 17 Jul 2023 21:08:25 +0200

Improved Daily Problem

Diffstat:
MProblems/0445.cpp|++++++++++++++++++++++++++++++++++++++---------------------------------

1 files changed, 38 insertions(+), 33 deletions(-)

diff --git a/Problems/0445.cpp b/Problems/0445.cpp

@@ -1,38 +1,43 @@

class Solution {
public:
string addStrings(string num1, string num2) {
if (num1 == "0" && num2 == "0") return "0";
string res = "";
int i = num1.size() - 1;
int j = num2.size() - 1;
int add = 0;
while (i >= 0 || j >= 0 || add) {
if (i >= 0) add += num1[i--] - '0';
if (j >= 0) add += num2[j--] - '0';
res += to_string(add % 10);
add /= 10;
pair<ListNode*, int> reverse(ListNode *root) {
ListNode *l = nullptr, *c = root;
int size = 0;
while(c) {
ListNode *n = c->next;
c->next = l;
l = c;
c = n;
size++;
}
return {l, size};
}
reverse(res.begin(), res.end());
return res;
}
ListNode *addTwoNumbers(ListNode *l1, ListNode *l2) {
if (!l1 || !l2) return nullptr;
string s1 = "", s2 = "";
for (ListNode *p = l1; p; p = p->next) s1 += '0' + p->val;
for (ListNode *p = l2; p; p = p->next) s2 += '0' + p->val;
string s = addStrings(s1, s2);
ListNode *h, *t;
t = h = new ListNode();
for (char c : s) t = t->next = new ListNode(c - '0');
return h->next;
}
ListNode* addTwoNumbers(ListNode* p1, ListNode* p2) {
auto [l1, s1] = reverse(p1);
auto [l2, s2] = reverse(p2);
if(s2 > s1) swap(l1, l2);
p1 = l1;
int carry = 0;
for(; l1 && l2; l1=l1->next, l2=l2->next) {
int sum = l1->val + l2->val + carry;
l1->val = sum % 10;
carry = sum / 10;
}
if(l1) {
while(true) {
int sum = l1->val + carry;
l1->val = sum % 10;
carry = sum / 10;
if(!l1->next) break;
l1 = l1->next;
}
}
if(!carry) return reverse(p1).first;
return new ListNode(carry, reverse(p1).first);
}
};