Submission #81827

#	Time	Username	Problem	Language	Result	Execution time	Memory
81827		mra2322001	XOR (IZhO12_xor)	C++14	0 / 100	2045 ms	25776 KiB

xor

#include <bits/stdc++.h>
#define f0(i, n) for(int i(0); i < (n); i++)
#define f1(i, n) for(int i(1); i <= n; i++)
#define bit(x, y) (((x) >> (y))&(1ll))

using namespace std;
typedef long long ll;
const int N = 250002;

int n, a[N], f[N], xo;
map <int, int> g;

void init(int b){
    g.clear();
    f0(i, n + 1){
        int x = f[i] >> b;
        g[x] = i;
    }
}

int main(){
    ios_base::sync_with_stdio(0);

    scanf("%d%d", &n, &xo);
    f1(i, n) scanf("%d", &a[i]), f[i] = f[i - 1]^a[i], g[f[i]] = i;

    int res = 0, ans = 0;
    f0(i, n + 1){
        int cur = xo ^ f[i];
        int x = g[cur] - i;
        if(x > res) res = x, ans = i + 1;
    }
    for(int b = 29; b >= 0; b--){
        if(bit(xo, b)) continue;
        int now = (xo >> b);
        now ++;
        init(b);
        f0(i, n + 1){
            int x = f[i] >> b;
            int cur = now ^ x;
            int t = g[cur] - i;
            if(t > res) res = t, ans = i + 1;
            else if(t==res){
                if(i + 1 < ans) ans = i + 1;
            }
        }
    }
    printf("%d %d", ans, res);
}

Compilation message (stderr)

xor.cpp: In function 'int main()':
xor.cpp:24:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d", &n, &xo);
     ~~~~~^~~~~~~~~~~~~~~~~
xor.cpp:25:54: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     f1(i, n) scanf("%d", &a[i]), f[i] = f[i - 1]^a[i], g[f[i]] = i;
              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~

• Subtask 1: 0 / 100