Submission #769591

#	Time	Username	Problem	Language	Result	Execution time	Memory
769591		GordonRemzi007	XORanges (eJOI19_xoranges)	C++17	100 / 100	425 ms	7896 KiB

xoranges

#include <iostream>
#include <vector>
#include <cmath>

using namespace std;

class SegmentTree {
    int n, i = 0;
    vector<int> seggy;
public:
    SegmentTree(int size):n(size) {
        seggy = vector<int>(2*n);
    }
    void push(int x) {
        seggy[n+i] = x;
        i++;
    }
    void build() {
        for(int i = n-1; i > 0; i--) seggy[i] = seggy[2*i]^seggy[2*i+1];
    }
    void update(int x, int y) {
        x+=n;
        seggy[x] = y;
        while(x > 1) {
            x/=2;
            seggy[x] = seggy[2*x]^seggy[2*x+1];
        }
    }
    int query(int x, int y) {
        int res = 0;
        for (x+=n, y+=n+1; x<y; x/=2, y/=2) {
            if (x&1) res ^= seggy[x++];
            if (y&1) res ^= seggy[--y];
        }
        return res;
    }
};

int main() {
    int n, q, t, x, y;
    cin >> n >> q;
    SegmentTree S1(n/2), S2((n+1)/2);
    for(int i = 0; i < n; i++) {
        cin >> x;
        if(i%2) S1.push(x);
        else S2.push(x);
    }
    S1.build();
    S2.build();
    while(q--) {
        cin >> t >> x >> y;
        x--;
        if(t == 1) {
            if(x%2) S1.update((x-1)/2, y);
            else S2.update(x/2, y);
        } else {
            y--;
            if((y-x+1)%2 == 0) cout << "0\n";
            else {
                if(x%2) cout << S1.query((x-1)/2, (y-1)/2) << "\n";
                else cout << S2.query(x/2, y/2) << "\n";
            }
        }
    }
}

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