Submission #1085487

#	Time	Username	Problem	Language	Result	Execution time	Memory
1085487		Sunbae	XOR (IZhO12_xor)	C++17	0 / 100	0 ms	348 KiB

xor

#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 5;
int a[N], has[32][N], qs[N], f[32];
signed main(){
	int n, x, t, mx; scanf("%d %d", &n, &x); 
	if(!x){ printf("1 %d", n); return 0;}	
	t = mx = 31 - __builtin_clz(x);
	memset(f, -1, sizeof(f));
	for(int i = 0; i<n; ++i){
		scanf("%d", a+i); 
		qs[i] = (i ? qs[i-1] : 0) ^ a[i];
		int f_b = 31 - __builtin_clz(a[i]);
		mx = max(mx, f_b);
		for(int j = 0; j<=f_b; ++j){
			if(a[i]>>j&1){
				has[j][i] = 1; 
				if(f[j] == -1) f[j] = i;
			}
		}				
	}
	int mx_len = 0, min_st = n;
	for(int j = t+1; j<=mx; ++j){
		int r_s = 0;
		for(int i = 0; i<n; ++i){
			r_s += has[j][i];
			if(r_s&1){
				int len = i+1, st = 1;
				if(len > mx_len) mx_len = len, min_st = st;
				else if(len == mx_len && st < min_st) min_st = st;
			}else if(f[j] != -1 && f[j] < i){
				int len = i - f[j], st = f[j]+2;
				if(len > mx_len) mx_len = len, min_st = st;
				else if(len == mx_len && st < min_st) min_st = st;
			}
		}
	}
	int r_s = 0;
	for(int i = 0, j = t; i<n; ++i){
		r_s += has[j][i];
		if((r_s&1) && qs[i] >= x){
			int len = i+1, st = 1;
			if(len > mx_len) mx_len = len, min_st = st;
			else if(len == mx_len && st < min_st) min_st = st;
		}else if((f[j] != -1) && (f[j] < i) && ((qs[i] ^ qs[f[j]]) >= x)){
			int len = i - f[j], st = f[j]+2;
			if(len > mx_len) mx_len = len, min_st = st;
			else if(len == mx_len && st < min_st) min_st = st;
		}
	}
	printf("%d %d", min_st, mx_len);
}

Compilation message (stderr)

xor.cpp: In function 'int main()':
xor.cpp:6:24: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
    6 |  int n, x, t, mx; scanf("%d %d", &n, &x);
      |                   ~~~~~^~~~~~~~~~~~~~~~~
xor.cpp:11:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   11 |   scanf("%d", a+i);
      |   ~~~~~^~~~~~~~~~~

• Subtask 1: 0 / 100