[NOI2009]变换序列
Description
Input
Output
Sample Input
5
1 1 2 2 1
Sample Output
1 2 4 0 3
HINT
30%的数据中N≤50;
60%的数据中N≤500;
100%的数据中N≤10000。
对于每个点,向它应该放置的位置连一条边,然后跑一遍匈牙利,连边的时候记得考虑顺序,使得字典序最小;然后匈牙利算法匹配的时候,会优先考虑当前点,腾出其他点的空间,于是我们倒序枚举即可
/*program from Wolfycz*/
#include<cmath>
#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
#define inf 0x7f7f7f7f
using namespace std;
typedef long long ll;
typedef unsigned int ui;
typedef unsigned long long ull;
inline char gc(){
static char buf[1000000],*p1=buf,*p2=buf;
return p1==p2&&(p2=(p1=buf)+fread(buf,1,1000000,stdin),p1==p2)?EOF:*p1++;
}
inline int frd(){
int x=0,f=1; char ch=gc();
for (;ch<'0'||ch>'9';ch=gc()) if (ch=='-') f=-1;
for (;ch>='0'&&ch<='9';ch=gc()) x=(x<<3)+(x<<1)+ch-'0';
return x*f;
}
inline int read(){
int x=0,f=1; char ch=getchar();
for (;ch<'0'||ch>'9';ch=getchar()) if (ch=='-') f=-1;
for (;ch>='0'&&ch<='9';ch=getchar()) x=(x<<3)+(x<<1)+ch-'0';
return x*f;
}
inline void print(int x){
if (x<0) putchar('-'),x=-x;
if (x>9) print(x/10);
putchar(x%10+'0');
}
const int N=1e4;
int path[N+10],vis[N+10],Ans[N+10],f[2][N+10],Time;
bool Extra(int x){
for (int i=0;i<2;i++){
int son=f[i][x];
if (vis[son]==Time) continue;
vis[son]=Time;
if (!~path[son]||Extra(path[son])){
path[son]=x;
return 1;
}
}
return 0;
}
int main(){
memset(path,255,sizeof(path));
int n=read(),res=0;
for (int i=0;i<n;i++){
int tmp=read(),x=(i-tmp+n)%n,y=(i+tmp)%n;
if (x>y) swap(x,y);
f[0][i]=x,f[1][i]=y;
}
for (int i=n-1;~i;i--){
++Time;
if (Extra(i)) res++;
}
if (res!=n){
printf("No Answer\n");
return 0;
}
for (int i=0;i<n;i++) Ans[path[i]]=i;
for (int i=0;i<n;i++) printf("%d",Ans[i]),putchar(i==n-1?'\n':' ');
return 0;
}