2019牛客暑期多校训练营（第三场）J LRU management

• 介个博客的意义是记录dubug的一天
• bug来源：当重复插入的是链表中唯一一个元素时。。整个链表会消失orz。。特判了一下就过了。。本来都不报希望了orz
  ps：手动模拟链表好累啊QAQ
• 代码：

#include<bits/stdc++.h>
using namespace std;
struct lis{
string s;
int v;
int f,b;
}l[1000005];
unordered_map<string,int> m;
int main(){
int t;
scanf("%d",&t);
while(t--){
m.clear();
int n,k;
scanf("%d %d",&n,&k);
int back=-1;
int front=-1;
int size=0;
while(n--){
int op,x;
char ss[13];
scanf("%d %s %d",&op,ss,&x);
string s(ss);
if(op==0){
if(!m.count(s)||m[s]==-1){
back++;
l[back].s=s;
if(size!=0) {
l[back].f=back-1;
l[back-1].b=back;
l[back].v=x;
}
else {
l[back].v=x;
front=back;
l[back].f=-1;
}
l[back].b=-1;
size++;
m[s]=back;
printf("%d\n",x);
}
else{
int gps=m[s];
int ff=l[gps].f;
int bb=l[gps].b;
if(ff==-1&&bb==-1) {//处理的bug
printf("%d\n",l[gps].v);
continue;
}
if(ff!=-1) l[ff].b=l[gps].b;
else front=bb,l[bb].f=-1;
if(bb!=-1) l[bb].f=l[gps].f;
else back=ff,l[ff].b=-1;

printf("%d\n",l[gps].v);

l[back].b=back+1;
back++;
l[back].s=s;
l[back].v=l[gps].v;
l[back].b=-1;

l[back].f=back-1;
m[s]=back;
}
if(size>k){
m[l[front].s]=-1;
l[l[front].b].f=-1;
front=l[front].b;
size--;
}
int no=front;
}
else{
if(!m.count(s)||m[s]==-1) {
printf("Invalid\n");
continue;
}
int g=m[s];
if(x==0){
printf("%d\n",l[g].v);
}
else if(x==-1){
if(l[g].f!=-1){
printf("%d\n",l[l[g].f].v);
}
else{
printf("Invalid\n");
}
}
else if(x==1){
if(l[g].b!=-1){
printf("%d\n",l[l[g].b].v);
}
else{
printf("Invalid\n");
}
}
}
}
}
}
/*
10
10 10
0 1 0
0 2 1
0 3 2
0 4 3
0 1 4
0 3 5
0 4 6
1 1 -1
1 4 1
1 2 1

8 3
0 0101010 1
0 0101011 2
1 0101010 1
0 1100000 3
0 0101011 -1
0 1111111 4
1 0101011 -1
1 0101010 0

1
5 1
0 0 10
0 00 20
1 0 1
1 00 -1
*/