1025 反转链表 测试点3和测试点6

易错点

测试点3：k=1的情况

测试点6：有无效结点，此时结点总个数不等于要反转的链表的结点总个数

代码

#include <iostream>
#include <cstdio>
#include <string>
using namespace std;
int a[100001];
string nxt[100001];
string p[100001];
int main()
{
	string faddr;
	int n,k;
	string address;
	int data;
	string nex;
	string final;
	string f;
	string tmpf;
	string fir;
	string tmpf2;
	int tmp=0;
	int tmp2=0;
	int len=1;
	cin>>faddr>>n>>k;
	for(int i=0;i<n;i++){
		cin>>address>>data>>nex;
		a[stoi(address)]=data;
		nxt[stoi(address)]=nex;
		if(nex=="-1"){
			final=address;
		}
	}
	f=faddr;
	p[stoi(f)]="-1";
	while(nxt[stoi(f)]!="-1"){
		p[stoi(nxt[stoi(f)])]=f;
		f=nxt[stoi(f)];
		len++;
	}
	f=final;
	if(k!=1){
		if(len%k>=2){
			for(int i=0;i<len%k-1;i++){
				f=p[stoi(f)];
			}
			tmpf=f;
			fir=p[stoi(f)];
		}	
		else if(len%k==1){
			tmpf=f;
			fir=p[stoi(f)];
		}
		else if(len%k==0){
			tmpf="-1";
			tmp2=1;
		}
		while(p[stoi(f)]!="-1"){
			if(tmp2==1){
				fir=f;
				tmp2=0;
				nxt[stoi(f)]=p[stoi(f)];
				for(int i=0;i<k-2;i++){
					f=p[stoi(f)];
					nxt[stoi(f)]=p[stoi(f)];
				}
				
			}
			else{
				fir=p[stoi(f)];
				for(int i=0;i<k-1;i++){
					f=p[stoi(f)];
					nxt[stoi(f)]=p[stoi(f)];
				}	
			}
			f=p[stoi(f)];
			nxt[stoi(f)]=tmpf;
			tmpf=fir;	
			if(p[stoi(f)]!="-1"){
				fir=p[stoi(f)];
			}	
		}	
	}
	else if(k==1){
		fir=faddr;
	}

	
	f=fir;
	while(nxt[stoi(f)]!="-1"){
		cout<<f<<" "<<a[stoi(f)]<<" "<<nxt[stoi(f)]<<endl;
		f=nxt[stoi(f)];
	}
	cout<<f<<" "<<a[stoi(f)]<<" "<<nxt[stoi(f)]<<endl;
	
	
	return 0;
}