P7115 [NOIP2020] 移球游戏 题解

题目

不太想说了，NOIP2020T3

P7115 [NOIP2020] 移球游戏

题解

某位大佬写的

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;
}