Submission #444114

#	Time	Username	Problem	Language	Result	Execution time	Memory
444114		idas	XORanges (eJOI19_xoranges)	C++17	100 / 100	137 ms	12564 KiB

xoranges

#include <bits/stdc++.h>
#define FOR(i, begin, end) for(long long i = (begin); i < (end); i++)
#define FAST_IO ios_base::sync_with_stdio(0); cin.tie(nullptr); cout.tie(nullptr)
#define F first
#define S second
#define PB push_back
#define MP make_pair
#define SZ(x) ((int)((x).size()))
#define LE(vec) vec[vec.size()-1]
#define TSTS int t; cin >> t; while(t--)solve()

const int INF = 1e9;
const long long LINF = 1e18;
const long double PI = asin(1)*2;
const int MOD = 1e9+7;

using namespace std;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef map<int, int> mii;
typedef long long ll;
typedef long double ld;

void setIO()
{
    FAST_IO;
}

void setIO (string s) {
    setIO();
 	freopen((s+".in").c_str(),"r",stdin);
 	freopen((s+".out").c_str(),"w",stdout);
}

const int N=2e5+10;
int n, q; ll to[2*N], te[2*N];

void build()
{
    for(int i=n-1; i>0; i--){
        to[i]=to[i<<1]^to[i<<1|1];
        te[i]=te[i<<1]^te[i<<1|1];
    }
}

void upd(int p, int x)
{
    if(p&1){
        for(to[p+=n]=x; p>1; p>>=1) to[p>>1]=to[p]^to[p^1];
    }
    else{
        for(te[p+=n]=x; p>1; p>>=1) te[p>>1]=te[p]^te[p^1];
    }
}

int ans(int l, int r)
{
    int ret=0;
    if((r-l)&1){
        if(l&1){
            for(l+=n, r+=n; l<r; l>>=1, r>>=1){
                if(l&1) ret^=to[l++];
                if(r&1) ret^=to[--r];
            }
        }
        else{
            for(l+=n, r+=n; l<r; l>>=1, r>>=1){
                if(l&1) ret^=te[l++];
                if(r&1) ret^=te[--r];
            }
        }
    }
    return ret;
}

int main()
{
    setIO();
    cin >> n >> q;
    FOR(i, 0, n)
    {
        if(i&1) cin >> to[i+n];
        else cin >> te[i+n];
    }
    build();
    FOR(i, 0, q)
    {
        int in;
        cin >> in;
        if(in&1){
            int p, x;
            cin >> p >> x;
            upd(p-1, x);
        }
        else{
            int l, r;
            cin >> l >> r;
            cout << ans(l-1, r) << '\n';
        }
    }
}

Compilation message (stderr)

xoranges.cpp: In function 'void setIO(std::string)':
xoranges.cpp:31:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   31 |   freopen((s+".in").c_str(),"r",stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
xoranges.cpp:32:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   32 |   freopen((s+".out").c_str(),"w",stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 12 / 12
• Subtask 2: 18 / 18
• Subtask 3: 25 / 25
• Subtask 4: 20 / 20
• Subtask 5: 25 / 25