蒟蒻的代码：

/*
Author: gsczl71
Copyright (c) 2023 gsczl71 All rights reserved.
problem：
*/

//#pragma omp parallel for num_threads(64)
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx")
//#pragma GCC optimize(2,3,"Ofast","inline","-fgcse","-fgcse-lm","-fipa-sra","-ftree-pre","-ftree-vrp","-fpeephole2","-ffast-math","-fsched-spec","unroll-loops","-falign-jumps","-falign-loops","-falign-labels","-fdevirtualize","-fcaller-saves","-fcrossjumping","-fthread-jumps","-funroll-loops","-freorder-blocks","-fschedule-insns","inline-functions","-ftree-tail-merge","-fschedule-insns2","-fstrict-aliasing","-falign-functions","-fcse-follow-jumps","-fsched-interblock","-fpartial-inlining","no-stack-protector","-freorder-functions","-findirect-inlining","-fhoist-adjacent-loads","-frerun-cse-after-loop","inline-small-functions","-finline-small-functions","-ftree-switch-conversion","-foptimize-sibling-calls","-fexpensive-optimizations","inline-functions-called-once","-fdelete-null-pointer-checks")
//#pragma GCC target("sse,sse2,sse3,sse4,popcnt,abm,mmx,avx,avx2")
//#pragma comment(linker,"/stack:200000000")
//#pragma GCC optimize("Ofast,no-stack-protector")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
//--------------------------------------------------------火车头

#include<bits/stdc++.h>
#include<vector> //有历史意义，我不想成为下一个hzlqwq
//#include<windows.h>

//--------------------------------------------------------头文件

#define ll long long
//#define int unsigned long long
#define i128 __int128
#define ull unsigned long long
#define pii pair<int,int>
#define fir first
#define se second
#define endl '\n'
#define debug puts("AK IOI RP INF")
#define debug1 puts("AK IOI -- part 1")
#define debug2 puts("AK IOI -- part 2")
#define debug3 puts("AK IOI -- part 3")
#define debug4 puts("AK IOI -- part 4")
#define re register
#define Yes puts("Yes")
#define No puts("No")
#define YES puts("YES")
#define NO puts("NO")
#define yes puts("yes")
#define no puts("no")
#define error puts("error")
#define IMPOSSIBLE puts("IMPOSSIBLE")
#define Impossible puts("Impossible")
#define fy puts("-1")
#define pll pair<long long, long long>
#define AC exit(0)
#define pb push_back

//-------------------------------------------------------define好习惯

using namespace std;
namespace gsczl71_function{
	inline int Min(int a, int b) {	return a < b ? a : b;}//取min
	inline int Max(int a, int b) {	return a > b ? a : b;}//取max
	inline void Swap(int& a,int& b) {a^=b,b^=a,a^=b;}//交换
	inline void tomin(int& a,int b) {if(a>b)a=b;}//a=min(a,b)
	inline void tomax(int& a,int b) {if(a<b)a=b;}//a=max(a,b)
	inline int Abs(int x){return (x^(x>>31))-(x >> 31);}//绝对值
	inline ll gcd(ll a,ll b){/*最大公因数*/int i=__builtin_ctz(a),j=__builtin_ctz(b),x=i>j?j:i,y;b>>=j;while(a){a>>=i;y=b-a;i=__builtin_ctz(y);b=a<b?a:b;a=y<0?-y:y;}return b<<x;}
	inline ll lcm(ll a,ll b){return a/gcd(a,b)*b;}//最小公倍数
	inline ll jc(ll x,ll p){ll res=1;if(p)for(ll i(1);i<=x;++i)res=(res*i)%p;else for(ll i(1);i<=x;++i)res=(res*i);return res;}//x的阶乘模p
	inline ll Mod(ll x, ll y){return x - y * (x / y);}//取模
	inline ll ksm(ll a,ll b){ll res=1;while(b){if(b & 1) res *= a;a *= a,b >>= 1;}return res;}//快速幂
	inline ll ksm(ll a,ll b,ll p){ll res=1;while(b){if(b & 1) res = (res * a) % p;a = (a * a) % p,b >>= 1;}return res;}//快速幂模p
}
namespace gsczl71_fastIO {
	template <typename T = int>
	inline T read() {
		T s=0,w=1;char c=getchar();
		while(!isdigit(c)){if(c=='-')w=-1;c=getchar();}
		while(isdigit(c))s=(s<<1)+(s<<3)+(c^48),c=getchar();
		return s*w;
	}template <typename T>
	inline void read(T &s){s=0;int w=1;char c=getchar();
		while(!isdigit(c)){if(c=='-')w=-1;c=getchar();}
		while(isdigit(c))s=(s<<1)+(s<<3)+(c^48),c=getchar();
		s*=w;
	}template <typename T, typename... Args> inline void read(T &x, Args &...args) {read(x), read(args...);}
	template <typename T>
	inline void write(T x,char ch) {
		if(x<0)x=-x,putchar('-');
		static char stk[200];
		int top=0;do{stk[top++]=x%10+'0',x/=10;}while(x);
		while(top)putchar(stk[--top]);
		putchar(ch);return;
	}
}
//using namespace gsczl71_fastIO;
//using namespace gsczl71_function;
//-------------------------------------------------------主程序-----------------------------------------------------
#define int long long
const int mod = 1e9+7;
//const int mod = 998244353;
const int inf = 0x3f3f3f3f,N = 5e5+5,M = 2e5+5;
const ll linf = 0x3f3f3f3f3f3f3f3f;
int fa[N][30],res=0; 
#define ui unsigned int
ui s;

inline ui get(ui x) {
	x ^= x << 13;
	x ^= x >> 17;
	x ^= x << 5;
	return s = x; 
}
ui ans[N];
int gen,dep[N];
vector<int> mp[N];
void dfs(int x,int fa){
	for(auto it:mp[x]){
		if(it==fa)continue;
		dep[it]=dep[x]+1;
		dfs(it,x);
	}return ;
}
void solve(){
	int n,q;
	cin >> n >> q >> s;
	for(int i = 1; i <= n;i++){
		cin >> fa[i][0];
		if(fa[i][0]==0) gen=i;
		else mp[fa[i][0]].push_back(i);
	}
	dep[gen]=1;
	dfs(gen,0);
	
	for(int i = 1;i <= 28;i++){
		for(int j = 1;j <= n;j++){
			fa[j][i]=fa[fa[j][i-1]][i-1];
		}
	}
	for(int i = 1;i <= q;i++){
		int x,k;
		x=((get(s)^ans[i-1])%n)+1;
		k = (get(s) ^ans[i-1]) % dep[x];
		for(int j = 0;j <= 28;j++){
			if((1<<j) & k) x=fa[x][j];
		}ans[i]=x;
		
	}
	res=ans[1];
	for(int i=2;i<=q;i++) res^=ans[i]*i;
	cout<<res;
	
}

signed main(){
//	freopen("std.in","r",stdin);
//	freopen("std.out","w",stdout);
//	unsigned long long RP = -1;
	ios::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
	int T=1;
//	cin >> T;
	while(T--) solve();
	return 0;//华丽收尾
}
	

样例没过，但蒟蒻认为这样写应该是对的？可是题解区貌似并没有这样的写法。