Submission #101908

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Source Code Expand

#include <cstdio>
#include <vector>
#include <map>
#include <set>
#include <algorithm>
#define rep(i, n) for(int i = 0; i < (n); ++i)
#define mp make_pair
#define all(v) (v).begin(), (v).end()
using namespace std;
typedef pair<int,int> P;
typedef pair<int,P> Q;

const int MX = 100005, n20 = 1<<20;

int a[MX];
int ans, as, at;
int t[MX*20][2], ti, o[MX*20];

void add(int x, int no){
    int v = 0;
    for(int i = 19; i >= 0; i--){
        int y = (x>>i&1);
        if(t[v][y] == -1){
            t[v][y] = ti;
            v = ti++;
            o[v] = no;
            t[v][0] = -1;
            t[v][1] = -1;
        } else {
            v = t[v][y];
        }
    }
}

void sch(int x, int no){
    int v = 0, s = x;
    for(int i = 19; i >= 0; i--){
        int y = !(x>>i&1);
        if(t[v][y] != -1 && o[t[v][y]] <= no){
            v = t[v][y];
            s ^= (y<<i);
        } else if(t[v][y^1] != -1 && o[t[v][y^1]] <= no){
            v = t[v][y^1];
            s ^= ((y^1)<<i);
        } else {
            if(x >= ans){
                ans = x;
                as = 1; at = no+1;
                return;
            }
        }
    }
    
    if(s > ans || (s==ans && o[v]+1 <= as)){
        ans = s;
        as = o[v]+1; at = no+1;
    }
}

int main(){
	int n;
	scanf("%d",&n);
    int sum = 0;
    t[ti][0] = -1;
    t[ti++][1] = -1;
    ans = -1;
    
    rep(i,n){
        scanf("%d",&a[i]);
        add(sum,i);
        sum ^= a[i];
    }
    
    for(int i = n-1; i >= 0; i--){
        sch(sum,i);
        sum ^= a[i];
    }
	
	printf("%d %d %d\n", ans, as, at);
    
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:62:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
./Main.cpp:69:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]

Judge Result