NC10 大数乘法

NC10 大数乘法

#include <string>
#include <vector>
class Solution {public:string solve(string s, string t) {int m = s.size(), n = t.size();reverse(s.begin(), s.end());reverse(t.begin(), t.end());//1.无进位相加并相乘vector<int> tmp(m + n);for (int i = 0; i < m; i++) {for (int j = 0; j < n; j++) {tmp[i + j] += (s[i] - '0') * (t[j] - '0');}}//2.处理进位int c = 0;string ans;for (auto x : tmp) {c = c + x;ans += c % 10 + '0';c = c / 10;}while (c) {ans += c % 10 + '0';c /= 10;}//3.处理前置0while (ans.size() > 1 && ans.back() == '0') ans.pop_back();reverse(ans.begin(), ans.end());return ans;}
};

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NC1 大数加法

NC1 大数加法

#include <type_traits>
class Solution {
public:string solve(string s, string t) {int i=s.size()-1,j=t.size()-1;int tmp=0;  //进位符string ans;while(i>=0||j>=0||tmp){int sum=0;if(i>=0) tmp+=s[i--]-'0';if(j>=0) tmp+=t[j--]-'0';ans+=tmp%10+'0';tmp/=10;}reverse(ans.begin(),ans.end());return ans;}
};

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NC40 链表相加(二)

NC40 链表相加(二)

/*** struct ListNode {*	int val;*	struct ListNode *next;*	ListNode(int x) : val(x), next(nullptr) {}* };*/
#include <new>
class Solution {
public:ListNode* reverse(ListNode* head){ListNode* newhead=new ListNode(0);ListNode* cur=head;while(cur){ListNode* next=cur->next;cur->next=newhead->next;newhead->next=cur;cur=next;}cur=newhead->next;delete newhead;return cur;}ListNode* addInList(ListNode* head1, ListNode* head2) {//逆序head1=reverse(head1),head2=reverse(head2);ListNode *cur1=head1,*cur2=head2;ListNode *ret=new ListNode(0);ListNode *prve=ret;int t=0;while(cur1||cur2||t){if(cur1){t+=cur1->val;cur1=cur1->next;}if(cur2){t+=cur2->val;cur2=cur2->next;}prve=prve->next=new ListNode(t%10);t/=10;}cur1=ret->next;delete ret;return reverse(cur1);}
};