题目
不太想说了,NOIP2020T3
题解
代码
#include<cstdio>
#include<algorithm>
int n,m;
int ans[820001][2],len;
struct line{
int a[405],top,id;
int pop(){int ret=a[top];a[top--]=0;return ret;}
void push(int x){a[++top]=x;}
int count(int x){
int ret=0;
for(int i=1;i<=top;i++)ret+=a[i]==x;
return ret;
}
}p[55];
struct IO{
static const int S=1<<21;
char buf[S],*p1,*p2;int st[105],Top;
~IO(){clear();}
inline void clear(){fwrite(buf,1,Top,stdout);Top=0;}
inline void pc(const char c){Top==S&&(clear(),0);buf[Top++]=c;}
inline char gc(){return p1==p2&&(p2=(p1=buf)+fread(buf,1,1<<21,stdin),p1==p2)?EOF:*p1++;}
inline IO&operator >> (char&x){while(x=gc(),x==' '||x=='
'||x=='r');return *this;}
template<typename T>inline IO&operator >> (T&x){
x=0;bool f=0;char ch=gc();
while(ch<'0'||ch>'9'){if(ch=='-') f^=1;ch=gc();}
while(ch>='0'&&ch<='9') x=(x<<3)+(x<<1)+ch-'0',ch=gc();
f?x=-x:0;return *this;
}
inline IO&operator << (const char c){pc(c);return *this;}
template<typename T>inline IO&operator << (T x){
if(x<0) pc('-'),x=-x;
do{st[++st[0]]=x%10,x/=10;}while(x);
while(st[0]) pc('0'+st[st[0]--]);return *this;
}
}fin,fout;
void move(int x,int y,int num=1){ //从x移到y
while(num--){
p[y].push(p[x].pop());
++len;ans[len][0]=p[x].id;ans[len][1]=p[y].id;
}
return ;
}
int main(){
freopen("P7115.in","r",stdin);
freopen("P7115.out","w",stdout);
fin>>n>>m;
for(int i=1;i<=n;i++){
p[i].top=m;p[i].id=i;
for(int j=1;j<=m;j++)fin>>p[i].a[j];
}
p[n+1].id=n+1;
if(n==2){
int p1_count_1=p[1].count(1);
move(2,3,p1_count_1);
while(p[1].top){if(p[1].a[p[1].top]==1)move(1,2);else move(1,3);}
move(2,1,p1_count_1);move(3,1,m-p1_count_1);move(3,2,p1_count_1);move(1,3,m-p1_count_1);
while(p[2].top){if(p[2].a[p[2].top]==1)move(2,1);else move(2,3);}
}
else {
for(int i=1;i<=n-2;i++){
int pi_count_x=p[i].count(i);
move(n,n+1,pi_count_x);
while(p[i].top)if(p[i].a[p[i].top]==i)move(i,n);else move(i,n+1);
move(n+1,i,m-pi_count_x);
while(p[i+1].top){//第i列成为全0列
if(p[i].top==m||p[i+1].a[p[i+1].top]==i)move(i+1,n+1);else move(i+1,i);
}
std::swap(p[i],p[n]);std::swap(p[i+1],p[n+1]);//第n列成全零列
for(int j=i;j<n;j++){
int pj_count_x=p[j].count(i);
move(n,n+1,pj_count_x);
while(p[j].top)if(p[j].a[p[j].top]==i)move(j,n);else move(j,n+1);
std::swap(p[j],p[n]);std::swap(p[n],p[n+1]);
}
for(int j=i;j<n;j++){
while(p[j].a[p[j].top]==i) move(j,n+1);
while(p[j].top!=m) move(n,j);
}
std::swap(p[i],p[n+1]);std::swap(p[n],p[n+1]);
}
std::swap(p[n-1],p[1]);std::swap(p[n],p[2]);std::swap(p[n+1],p[3]);
int p1_count_1=p[1].count(n-1);
move(2,3,p1_count_1);
while(p[1].top){if(p[1].a[p[1].top]==n-1)move(1,2);else move(1,3);}
move(2,1,p1_count_1);move(3,1,m-p1_count_1);move(3,2,p1_count_1);move(1,3,m-p1_count_1);
while(p[2].top){if(p[2].a[p[2].top]==n-1)move(2,1);else move(2,3);}
}
printf("%d
",len);
for(int i=1;i<=len;i++)fout<<ans[i][0]<<' '<<ans[i][1]<<'
';
return 0;
}