leetcode

4 两个排序数组的中位数

 1 class Solution {
 2 public:
 3     double findMedianSortedArrays(vector<int>& nums1, vector<int>& nums2) {
 4         int n=nums1.size(),m=nums2.size();
 5         if(n>m){
 6             swap(n,m);
 7             swap(nums1,nums2);
 8         }
 9         int l=0,r=n,mid1=0,mid2=0;
10         while(l<=r){
11             mid1=(l+r)>>1;
12             mid2=((n+m+1)>>1)-mid1;
13             if((mid1==0||mid2==m||nums1[mid1-1]<=nums2[mid2])&&(mid1==n||mid2==0||nums2[mid2-1]<=nums1[mid1])) break;
14             else if((mid1>0&&mid2<m&&nums1[mid1-1]>nums2[mid2])){
15                 r=mid1-1;
16             }else if(mid1<n&&mid2>0&&nums2[mid2-1]>nums1[mid1]){
17                 l=mid1+1;
18             }
19         }
20         cout<<"l r: "<<l<<' '<<r<<endl;
21         cout<<"mid1 mid2: "<<mid1<<' '<<mid2<<endl;
22         int maxL=0,minR=0;
23         if(mid1==0) maxL=nums2[mid2-1];
24         else if(mid2==0) maxL=nums1[mid1-1];
25         else maxL=max(nums1[mid1-1],nums2[mid2-1]);
26         if(mid1==n) minR=nums2[mid2];
27         else if(mid2==m) minR=nums1[mid1];
28         else minR=min(nums1[mid1],nums2[mid2]);
29         cout<<maxL<<' '<<minR<<endl;
30         if((n+m)%2==0) return (maxL+minR)/2.0;
31         else return maxL;
32     }
33 };
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5 最长回文字串

 1 class Solution {
 2 public:
 3     string longestPalindrome(string s) {
 4         string str="$+";
 5         for(int i=0;i<s.length();i++){
 6             str+=s[i];
 7             str+="+";
 8         }
 9         str+="%";
10         s=str;
11         cout<<s<<endl;
12         int maxl=0,n=s.length(),id=0,mx=0,d[2009];
13         string ans="";
14         memset(d,0,sizeof(d));
15         for(int i=1;i<n;i++){
16             if(i<mx){
17                 d[i]=min(mx-i,d[2*id-i]);
18             }else{
19                 d[i]=1;
20             }
21             while(s[i-d[i]]==s[i+d[i]]) d[i]++;
22             if(mx<i+d[i]){
23                 mx=i+d[i];
24                 id=i;
25             }
26             if(d[i]-1>maxl){
27                 maxl=d[i]-1;
28                 ans="";
29                 for(int j=i-d[i]+1;j<=i+d[i]-1;j++){
30                     if(s[j]!='+') ans+=s[j];
31                 }    
32             }
33         }
34         return ans;
35     }
36 };
View Code

10 正则表达式匹配

 1 class Solution {
 2 public:
 3     bool isMatch(string s, string p) {
 4         int n=s.length(),m=p.length();
 5         if(n==0&&m==0) return 1;
 6         if(n==1&&m==1) return s[0]==p[0]||p[0]=='.';
 7         if(p[1]!='*'){
 8             if(n==0) return 0;
 9             if(p[0]==s[0]||p[0]=='.') return isMatch(s.substr(1),p.substr(1));
10             else return 0;
11         }
12         while(!s.empty()&&(s[0]==p[0]||p[0]=='.')){
13             if(isMatch(s,p.substr(2))) return 1;
14             s=s.substr(1);
15         }
16         return p.length()>=2?isMatch(s,p.substr(2)):0;
17     }
18 };
View Code

 

posted @ 2018-09-18 11:50  ChenThree  阅读(147)  评论(0)  编辑  收藏  举报