wenbao与合肥网络赛

啦啦啦。。。只是签到题而已

异或密码

http://acm.hdu.edu.cn/showproblem.php?pid=5968

#include <iostream>
#include <string.h>
#include <stdio.h>
using namespace std;
int n, t, m, a[105], b[2050], x;
void lala(){
    for(int i = 2; i <= n; i++){
        int sum = 0;
        for(int j = 0; j < n; j++){
            if(j < i-1){
                sum ^= a[j];
            }else if(j == i-1){
                sum ^= a[j];
                b[sum] = i;
            }else{
                sum = sum ^a[j-i]^a[j];
                b[sum] = i;
            }
        }
    }
}
int main(){
    scanf("%d", &t);
    while(t--){
        scanf("%d", &n);
        for(int i = 0; i < n; i++){
            scanf("%d", &a[i]);
            b[a[i]] = 1;
        }
        lala();
        scanf("%d", &m);
        for(int j = 0; j < m; j++){
            scanf("%d", &x);
            for(int i = 0; ; i++){
                if(x+i < 2050 && b[x+i] && x-i >= 0 && b[x-i]) {
                    printf("%d
", max(b[x+i], b[x-i]));
                    break;
                }
                if(x+i < 2050 && b[x+i]){
                    printf("%d
", b[x+i]);
                    break;
                }
                if(x-i >= 0 && b[x-i]){
                    printf("%d
", b[x-i]);
                    break;
                }
            }
        }
        printf("
");
        memset(b, 0, sizeof(b));
    }
    return 0;
}

最大位或

http://acm.hdu.edu.cn/showproblem.php?pid=5969

#include <iostream>
#include <string.h>
#include <cmath>
#include <stdio.h>
using namespace std;
#define ll long long
int n, flag;
ll l, r, sum;
int a[66], b[66];
int main(){
    scanf("%d", &n);
    while(n--){
        scanf("%lld %lld", &l, &r);
        if(l == r) printf("%lld
", l);
        else{
            memset(a, 0, sizeof(a));
            memset(b, 0, sizeof(b));
            int i = 0, j = 0;
            sum = 0;
            while(l){
                a[i] = l%2, i++;
                l >>= 1;
            }
            while(r){
                b[j] = r%2, j++;
                r >>= 1;
            }
            int len = max(i, j);
            for(int k = len - 1; k >= 0; k--){
                if(a[k] == b[k]){
                    if(a[k] == 1){
                        sum += (ll)pow(2.0, k);
                    }
                }else{
                    sum += (ll)pow(2.0, k+1) -1;
                    break;
                }
            }
            printf("%lld
", sum);
        }
    }
    return 0;
}

只有不断学习才能进步！