Submission #844527

#	Time	Username	Problem	Language	Result	Execution time	Memory
844527		konber	XORanges (eJOI19_xoranges)	C++14	100 / 100	116 ms	13476 KiB

xoranges

#include <iostream>
#include <vector>

using namespace std;

vector<int> st1, st2, a;

void build(int p, int L, int R){
    if(L==R){
        if(L%2==0) st1[p] = a[L];
        else st2[p] = a[L];
        return;
    }

    build(2*p, L, (L+R)/2);
    build(2*p+1, (L+R)/2+1, R);
    st1[p] = st1[2*p]^st1[2*p+1];
    st2[p] = st2[2*p]^st2[2*p+1];
}

void update(int p, int L, int R, int pos, int v){
    if(L==R){
        if(L%2==0) st1[p] = v;
        else st2[p] = v;
        return;
    }

    int mid=(L+R)/2;
    if(pos <= mid)
        update(2*p, L, mid, pos, v);
    else
        update(2*p+1, mid+1, R, pos, v);
    st1[p] = st1[2*p]^st1[2*p+1];
    st2[p] = st2[2*p]^st2[2*p+1];

}

int rsq1(int p, int L, int R, int i, int j){
    if(j < L || i > R) return 0;
    if(L >= i && R <= j) return st1[p];

    int mid=(L+R)/2;
    return rsq1(2*p, L, mid, i, j)^rsq1(2*p+1, mid+1, R, i, j);
}

int rsq2(int p, int L, int R, int i, int j){
    if(j < L || i > R) return 0;
    if(L >= i && R <= j) return st2[p];

    int mid=(L+R)/2;
    return rsq2(2*p, L, mid, i, j)^rsq2(2*p+1, mid+1, R, i, j);
}

int main()
{
    int N, Q;
    scanf("%d%d", &N, &Q);
    a.resize(N+1);
    st1.resize(4*N+1);
    st2.resize(4*N+1);
    for(int i=1; i <= N; i++)
        scanf("%d", &a[i]);

    build(1, 1, N);
    while(Q--){
        int q, i, j;
        scanf("%d%d%d", &q, &i, &j);
        if(q==1){
            update(1, 1, N, i, j);
        }
        else{
            int ans;
            if((i%2)!=(j%2)) ans=0;
            else if(i%2==0)  ans = rsq1(1, 1, N, i, j);
            else ans = rsq2(1, 1, N, i, j);
            printf("%d\n", ans);
        }
    }
}

Compilation message (stderr)

xoranges.cpp: In function 'int main()':
xoranges.cpp:57:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   57 |     scanf("%d%d", &N, &Q);
      |     ~~~~~^~~~~~~~~~~~~~~~
xoranges.cpp:62:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   62 |         scanf("%d", &a[i]);
      |         ~~~~~^~~~~~~~~~~~~
xoranges.cpp:67:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   67 |         scanf("%d%d%d", &q, &i, &j);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~

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