三数之和》》。。

用户3519280

发布于 2023-07-08 10:51:56

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发布于 2023-07-08 10:51:56

文章被收录于专栏：c++ 学习分享

#include <stdio.h>
#include <iostream>
#include <vector>
//#include <map> 
#if(__cplusplus == 201103L)
 #include <unordered_map>
 #include <unordered_set>
 #else
 #include <tr1/unordered_map>
 #include <tr1/unordered_set>
 namespace std
 {
     using std::tr1::unordered_map;
     using std::tr1::unordered_set;
     //using std::tr1;
     //using std::tr1;
 }
 //#include<tr1/unordered_map>
//using namespace std::tr1;
 #endif
 //#include <unordered_map>
using namespace std;
//using namespace std::tr1;
vector<vector<int> > threeSum(vector<int>&);
int main(void) {
	cout<<"ans"<<endl;
	int out[6]={-1,0,1,5,3,4};
	vector<int> nums(out,out+6);
	nums.push_back(-1);
		nums.push_back(0);
			nums.push_back(1);
				nums.push_back(2);	
				nums.push_back(5);
				nums.push_back(6);
				cout<<nums.size()<<endl;
				for(int i=0;i<nums.size();i++){
			//mm(nums[i])=mm(nums[i])+nums[i];
			cout<<nums[i];
		}
	vector<vector<int> > ans;
	ans=threeSum(nums);
	//cout<<"ans"<<endl;
	//cout<<ans[0][0]<<"ans"<<endl;
		//cout<<ans[0][1]<<endl;
		//cout<<ans[0][2]<<endl;
		//cout<<"ans"<<endl;
	vector<vector<int> >::iterator tmp;
	for(int i=0;i<ans.size();i++){
			//mm(nums[i])=mm(nums[i])+nums[i];
			//cout<<ans[i][0];
		}
		//cout<<ans[0][0]<<"ans"<<endl;
		//cout<<ans[0][1]<<endl;
		//cout<<ans[0][2]<<endl;
    //for (tmp = ans.begin(); ans != nums.end(); ++tmp)
//    {
//        cout << "(" << tmp->first << ", " << tmp->second << ")" << " ";
//    }
    return 0;
}
unordered_map<int ,int> mm;
		//vector<vector<int> > ans;
vector<vector<int> > threeSum(vector<int>& nums) {
		//::sort(nums.begin(),nums.end());
		//vector<int>::iterator tmp;

    //for (tmp = nums.begin(); tmp != nums.end(); ++tmp)
//    {
//        cout << "(" << tmp->first << ", " << tmp->second << ")" << " ";
//    }
vector<vector<int> > ans;
		for(int i=0;i<nums.size();i++){
			//mm(nums[i])=mm(nums[i])+nums[i];
			
		}
		int preI=100000+10;
		int preJ=100000+10;
		for(int i=0;i<nums.size();i++){
			if(nums[i]==preI)continue;
			mm[nums[i]]--;
			
			for(int j=i+1;j<nums.size();j++){
				int find=0-nums[i]-nums[j];
				if(find>=nums[i]&&find>=nums[j]){
				if(mm[find]>0){
					//ans.push_back(vector<int>{nums[i],nums[j],find});
					vector<int> v;
					v.push_back(nums[i]);
						v.push_back(nums[j]);
							v.push_back(find);
					ans.push_back(v);
				}
				
			}
			mm[nums[j]]++;
			preJ=nums[j];
			}
			mm[nums[i]]++;
			preJ=nums[i];
			
		}
		return ans;
    }

#include <stdio.h>
#include <iostream>
#include <vector>
//#include <map> 
#if(__cplusplus == 201103L)
 #include <unordered_map>
 #include <unordered_set>
 #else
 #include <tr1/unordered_map>
 #include <tr1/unordered_set>
 namespace std
 {
     using std::tr1::unordered_map;
     using std::tr1::unordered_set;
     //using std::tr1;
     //using std::tr1;
 }
 //#include<tr1/unordered_map>
//using namespace std::tr1;
 #endif
 //#include <unordered_map>
using namespace std;
//using namespace std::tr1;
vector<vector<int> > threeSum(vector<int>&);
int main(void) {
	cout<<"ans"<<endl;
	int out[6]={-1,0,1,5,3,4};
	//vector<int> nums(out,out+6);
	vector<int> nums;
	nums.push_back(-1);
		nums.push_back(0);
			nums.push_back(1);
				nums.push_back(2);	
				nums.push_back(5);
				nums.push_back(6);
				cout<<nums.size()<<endl;
				for(int i=0;i<nums.size();i++){
			//mm(nums[i])=mm(nums[i])+nums[i];
			cout<<nums[i];
		}
	vector<vector<int> > ans;
	ans=threeSum(nums);
	//cout<<"ans"<<endl;
	//cout<<ans[0][0]<<"ans"<<endl;
		//cout<<ans[0][1]<<endl;
		//cout<<ans[0][2]<<endl;
		//cout<<"ans"<<endl;
	vector<vector<int> >::iterator tmp;
	for(int i=0;i<ans.size();i++){
			//mm(nums[i])=mm(nums[i])+nums[i];
			//cout<<ans[i][0];
		}
		//cout<<ans[0][0]<<"ans"<<endl;
		//cout<<ans[0][1]<<endl;
		//cout<<ans[0][2]<<endl;
    //for (tmp = ans.begin(); ans != nums.end(); ++tmp)
//    {
//        cout << "(" << tmp->first << ", " << tmp->second << ")" << " ";
//    }
    return 0;
}
unordered_map<int ,int> mm;
		//vector<vector<int> > ans;
vector<vector<int> > threeSum(vector<int>& nums) {
		//::sort(nums.begin(),nums.end());
		//vector<int>::iterator tmp;

    //for (tmp = nums.begin(); tmp != nums.end(); ++tmp)
//    {
//        cout << "(" << tmp->first << ", " << tmp->second << ")" << " ";
//    }
vector<vector<int> > ans;
		for(int i=0;i<nums.size();i++){
			//mm(nums[i])=mm(nums[i])+nums[i];
			
		}
		int preI=100000+10;
		int preJ=100000+10;
		for(int i=0;i<nums.size();i++){
			if(nums[i]==preI)continue;
			mm[nums[i]]--;
			
			for(int j=i+1;j<nums.size();j++){
				int find=0-nums[i]-nums[j];
				if(find>=nums[i]&&find>=nums[j]){
				if(mm[find]>0){
					//ans.push_back(vector<int>{nums[i],nums[j],find});
					vector<int> v;
					v.push_back(nums[i]);
						v.push_back(nums[j]);
							v.push_back(find);
					ans.push_back(v);
				}
				
			}
			mm[nums[j]]++;
			preJ=nums[j];
			}
			mm[nums[i]]++;
			preJ=nums[i];
			
		}
		return ans;
    }

ans的函数返回值总是不对，

ans没有值，是怎么回事？？？

vector<vector<int> > ans=threeSum(nums);

下面pushback是有值的，但是这方法也太笨了

#include <stdio.h>
#include <iostream>
#include <vector>
//#include <map> 
#if(__cplusplus == 201103L)
 #include <unordered_map>
 #include <unordered_set>
 #else
 #include <tr1/unordered_map>
 #include <tr1/unordered_set>
 namespace std
 {
     using std::tr1::unordered_map;
     using std::tr1::unordered_set;
     //using std::tr1;
     //using std::tr1;
 }
 //#include<tr1/unordered_map>
//using namespace std::tr1;
 #endif
 //#include <unordered_map>
using namespace std;
//using namespace std::tr1;
vector<vector<int> > threeSum(vector<int>&);
	vector<vector<int> > ans;
int main(void) {
	cout<<"ans"<<endl;
	int out[6]={-1,0,1,5,3,4};
	//vector<int> nums(out,out+6);
	vector<int> nums;
	nums.push_back(-1);
		nums.push_back(0);
			nums.push_back(1);
				nums.push_back(2);	
				nums.push_back(5);
				nums.push_back(6);
				cout<<nums.size()<<endl;
				for(int i=0;i<nums.size();i++){
			//mm(nums[i])=mm(nums[i])+nums[i];
			cout<<nums[i];
		}
	vector<vector<int> > ans=threeSum(nums);
	for(int i=0;i<threeSum(nums).size();i++){
		ans.push_back(threeSum(nums)[i]);
	}
	//ans=threeSum(nums);
	//cout<<"ans"<<endl;
	//cout<<ans[0][0]<<"ans"<<endl;
		//cout<<ans[0][1]<<endl;
		//cout<<ans[0][2]<<endl;
		//cout<<"ans"<<endl;
	vector<vector<int> >::iterator tmp;
	for(int i=0;i<ans.size();i++){
			//mm(nums[i])=mm(nums[i])+nums[i];
			//cout<<ans[i][0];
		}
		cout<<endl<<ans.size()<<"ans"<<endl;
		cout<<endl<<threeSum(nums).size()<<"ans"<<endl;
		//cout<<ans[0][0]<<"ans"<<endl;
		//cout<<ans[0][1]<<endl;
		//cout<<ans[0][2]<<endl;
    //for (tmp = ans.begin(); ans != nums.end(); ++tmp)
//    {
//        cout << "(" << tmp->first << ", " << tmp->second << ")" << " ";
//    }
    return 0;
}
unordered_map<int ,int> mm;
		//vector<vector<int> > ans;
vector<vector<int> > threeSum(vector<int>& nums) {
		//::sort(nums.begin(),nums.end());
		//vector<int>::iterator tmp;

    //for (tmp = nums.begin(); tmp != nums.end(); ++tmp)
//    {
//        cout << "(" << tmp->first << ", " << tmp->second << ")" << " ";
//    }
vector<vector<int> > ans;
		for(int i=0;i<nums.size();i++){
			//mm(nums[i])=mm(nums[i])+nums[i];
			
		}
		int preI=100000+10;
		int preJ=100000+10;
		for(int i=0;i<nums.size();i++){
			if(nums[i]==preI)continue;
			mm[nums[i]]--;
			
			for(int j=i+1;j<nums.size();j++){
				int find=0-nums[i]-nums[j];
				if(find>=nums[i]&&find>=nums[j]){
				if(mm[find]>0){
					//ans.push_back(vector<int>{nums[i],nums[j],find});
					vector<int> v;
					v.push_back(nums[i]);
						v.push_back(nums[j]);
							v.push_back(find);
					ans.push_back(v);
				}
				
			}
			mm[nums[j]]++;
			preJ=nums[j];
			}
			mm[nums[i]]++;
			preJ=nums[i];
			
		}
		return ans;
    }

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原始发表：2022-05-20，如有侵权请联系 cloudcommunity@tencent.com 删除

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