字节跳动2019届校招笔试题(小结)

#include<iostream>
#include<vector>
#include<string>
 
using namespace std;
 
int getNum(vector<vector<int>>& people,int i,int j,vector<vector<int>>& reach)
{
    int m=people.size(),n=people[0].size();
    if(i>=m||j>=n||i<0||j<0){
        return  0;
    }
    else if(people[i][j]==1&&reach[i][j]==0){
        reach[i][j]=1;
        int n1=getNum(people,i-1,j,reach)+getNum(people,i+1,j,reach);
       int n2=getNum(people,i,j-1,reach)+getNum(people,i,j+1,reach);
       int n3=getNum(people,i-1,j-1,reach)+getNum(people,i-1,j+1,reach);
       int n4=getNum(people,i+1,j-1,reach)+getNum(people,i+1,j+1,reach);
        return n1+n2+n3+n4+1;
    }else {
		return 0;}
    }
void getdata(vector<vector<int>>& people,vector<int>& num,vector<vector<int>>& reach)
{
    int m=people.size(),n=people[0].size();
    for(int i=0;i<m;i++)
        for(int j=0;j<n;j++) {
            if(people[i][j]==1&&reach[i][j]==0){
                int n=getNum(people,i,j,reach);
                num.push_back(n);
            }
        }
}
int main()
{
    int m;
    int n;
    char c;
    cin>>m>>c>>n;
    vector<vector<int> > people;
    vector<int> vtemp(n,0);
    vector<vector<int>> reach(m,vtemp);
    for(int i=0;i<m;i++){
		vector<int> ptemp;
		int temp;
		char cc;
		for(int j=0;j<n-1;j++){
			cin>>temp;
			cin>>cc;
			ptemp.push_back(temp);
		}
		cin>>temp;
		ptemp.push_back(temp);
	    people.push_back(ptemp);
	}
    vector<int>num;
    if(people.empty()){
        cout<<0<<','<<0<<endl;
        return 0;
    }
    getdata(people,num,reach);
    vector<int>::iterator max=max_element(nums.begin(),nums.end());
    cout<<num.size()<<","<<*max<<endl;
    return 0;
}

#include<iostream>
#include<vector>
#include<utility>
#include<algorithm>
 
using namespace std;
 
void mergeIndex(vector<pair<int,int>>& vp)
{
   sort(vp.begin(),vp.end(),[](pair<int,int>& temp1,pair<int,int>& temp2){return temp1.first<temp2.first;});
   int n=vp.size();
   for(auto it=vp.begin();it<vp.end()-1;)
   {
       if(it->second>=(it+1)->first-1)
         {
               if((it+1)->second>it->second){
                  it->second=(it+1)->second;
                }
               it=vp.erase(it+1);
               --it;
         }else{
             ++it;
         }
   }
}
int main()
{
   vector<pair<int,int>> vp;
  int m;
  cin>>m;
  int first,last;
  char c1,c2;
  for(int i=0;i<m;i++)
   {
      do
      {
        cin>>first;
        if(cin.get()==',')
          {
              cin>>last;
              vp.push_back(make_pair(first,last));
          }
       }while(cin.get()==';');
   }
   mergeIndex(vp);
   int i=0;
  for(;i<vp.size()-1;i++)
    {
        cout<<vp[i].first<<","<<vp[i].second<<";";
    }
  cout<<vp[i].first<<","<<vp[i].second<<endl;
  cout<<endl;
   return 0;
}

#include<iostream>
#include<vector>
#include<utility>
#include<algorithm>
using namespace std;
 
int main()
{
	int n;
	cin >> n;
	vector<pair<int, int>> vp;
	int a, b,cap=0;
	for(int i=0;i<n;i++){
		cin >> a >> b;
		vp.push_back(make_pair(a, b));
		cap = cap < a ? a : cap; 
	}
	sort(vp.begin(), vp.end(), [](pair<int, int>& p1, pair<int, int>& p2) {return p1.second > p2.second; });
	int** dp = new int* [n];
	for (int i = 0; i<n; i++){
		dp[i] = new int[cap+1];
	}
	for (int j = 0; j <=cap; j++) {
		dp[n-1][j] = 0;
	}
	for (int i = n-2; i>=0; i--){
		for (int j = 0; j <= cap; j++){
			int point1 = (j >=vp[i].first) ? dp[i + 1][j- vp[i].first] + vp[i].second : 0;   //x[i]和cap-x[i]不能确定谁大
			int point2 = (j<=cap- vp[i].first) ? dp[i + 1][j+ vp[i].first] + vp[i].second : 0;//这样省去了划分区间的麻烦
			dp[i][j] = max({ dp[i + 1][j], point1, point2 });
		}
	}      
	cout << dp[0][0] << endl;
	for (int i = 0; i < n; i++) {
		delete [] dp[i];
	}
	delete [] dp;
	return 0;
}

#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;
 
bool rfind(int s, int des, int n, int& length, int* reach, int* path, vector<vector<int>>& red)
{
	reach[s] = 1;
	for (int u = 1; u <= n; u++){
		if (red[s][u] != 0 && reach[u] == 0) {
			path[++length] = u;
			if (u == des || rfind(u, des, n, length, reach, path, red)) {
				return true;
			}
			length--;
		}
	}
	return false;
}
int* findPath(int begin, int end, int n, vector<vector<int>>& red)
{
	int* path = new int[n + 1];
	path[1] = begin;
	int length = 1;
	int des = end;
	int* reach = new int[n + 1];
	for (int i = 1; i <= n; i++) {
		reach[i] = 0;
	}
	if (begin == end || rfind(begin, des, n, length, reach, path, red)) {
		path[0] = length - 1;
	}
	else {
		delete[] path;
		path = NULL;
	}
	delete[] reach;
	return path;
}
int main()
{
	int n, m;
	cin >> n;
	cin >> m;
	vector<int> vtemp(n + 1, 0);
	vector<vector<int>> red(n + 1, vtemp);
	int row, col;
	for (int i = 0; i<m; i++){
		cin >> row >> col;
		red[row][col] = 1;
	}
	bool isred = true;
	int t = 0;
	for (int i = 1; i <= n; i++){
		isred = true;
		for (int j = 1; j <= n; j++){
			int* path = findPath(j, i, n, red);
			if (path == NULL){
				isred = false;
				break;
			}
			else {
				delete[] path;
			}
		}
		if (isred) {
			++t;
		}
	}
	cout << t << endl;
	return 0;
}