Update CHEFEXQ.cpp

Author: rachitiitr

Codechef/DEC17/CHEFEXQ.cpp

@@ -1 +1,115 @@
-will be added tomorrow once the contest ends..
+#include <bits/stdc++.h>
+// #include "stdafx.h"
+// #pragma warning(disable : 4996) //_CRT_SECURE_NO_WARNINGS
+using namespace std;
+#define gc getchar_unlocked
+#define fo(i,n) for(i=0;i<n;i++)
+#define Fo(i,k,n) for(i=k;k<n?i<n:i>n;k<n?i+=1:i-=1)
+#define ll long long
+#define si(x)	scanf("%d",&x)
+#define sl(x)	scanf("%lld",&x)
+#define ss(s)	scanf("%s",s)
+#define pi(x)	printf("%d\n",x)
+#define pl(x)	printf("%lld\n",x)
+#define ps(s)	printf("%s\n",s)
+#define deb(x) cout << #x << "=" << x << endl
+#define deb2(x, y) cout << #x << "=" << x << "," << #y << "=" << y << endl
+#define pb push_back
+#define mp make_pair
+#define F first
+#define S second
+#define all(x) x.begin(), x.end()
+#define clr(x) memset(x, 0, sizeof(x))
+#define sortall(x) sort(all(x))
+#define tr(it, a) for(auto it = a.begin(); it != a.end(); it++)
+#define PI 3.1415926535897932384626
+typedef pair<int, int>	pii;
+typedef pair<ll, ll>	pl;
+typedef vector<int>		vi;
+typedef vector<ll>		vl;
+typedef vector<pii>		vpii;
+typedef vector<pl>		vpl;
+typedef vector<vi>		vvi;
+typedef vector<vl>		vvl;
+int mpow(int base, int exp); 
+void ipgraph(int m);
+void dfs(int u, int par);
+const int mod = 1000000007;
+const int N = 3e5, M = N;
+//=======================
+
+vi g[N];
+int a[N];
+const int rtn = 600;
+int local[N], bkt[N];
+int mat[rtn+1][rtn+1];
+int dp[rtn+1][rtn+1], en[rtn+1];
+unordered_map<int, int> cnt[rtn+1];
+
+void compute(int b){
+	cnt[b].clear();
+	int i;
+	dp[b][0] = mat[b][0];
+	Fo(i, 1, en[b]+1){
+		dp[b][i] = mat[b][i] ^ dp[b][i-1];
+	}
+	Fo(i, 0, en[b]+1) cnt[b][dp[b][i]]++;
+}
+int main()
+{
+	//freopen("input.txt", "r", stdin);
+	//freopen("output.txt", "w", stdout);
+	ios_base::sync_with_stdio(false);
+	cin.tie(NULL);
+	int i,n,k,j, type, x, _i = 0, q;
+	int b = -1;
+	
+	si(n); si(q);
+	fo(i, n) {
+		si(a[i]);
+		if(i%rtn == 0){
+			if(b>=0) compute(b);
+			b++, _i = 0;
+		}
+		
+		bkt[i] = b;
+		local[i] = _i;
+		en[b] = _i;
+		mat[b][_i] = a[i];
+		_i++;
+	}
+	compute(b);
+	
+	while(q--){
+		si(type);
+		si(i);
+		si(x);
+		i--;
+		if(type == 1){
+			//update a[i] = x;
+			b = bkt[i];
+			_i = local[i];
+			mat[b][_i] = x;
+			compute(b);
+		}
+		else{
+			//query prefixes with xor = x, and end before i
+			int b = bkt[i];
+			int ans = 0, ptr = 0, pre = 0;
+			while(bkt[ptr] < b){
+				int cur_bkt = bkt[ptr];
+				int need = x ^ pre;
+				ans += cnt[cur_bkt][need];
+				pre ^= dp[cur_bkt][en[cur_bkt]];
+				ptr += rtn;
+			}
+			Fo(j, 0, local[i]+1){
+				pre ^= mat[b][j];
+				if(pre == x) ans++;
+			}
+			printf("%d\n", ans);
+		}
+	}
+
+	return 0;
+}