牛客练习赛42

题目链接https://ac.nowcoder.com/acm/contest/393#question

 

A-字符串

这题只要找两个字符串公共最长子串就好了，O(n)

其中LCS=LCP=最长公共子串

#include<iostream>
#include<stack>
#include<cstdio>
#include<cmath>
#include<queue>
#include<cstring>
#include<string>
#include<algorithm>
using namespace std;
typedef long long ll;
const int maxn = 200000+10;
const int inf = 0x7fffffff;
const int mod = 100000007;
//==========================
 
string a, b;
int n;
int main()
{
    cin >> a >> b;
    int res = 0,t=0;
    for (int i = 0; i <a.length() ; i++){
        //cout << a[i] << "--" << b[i] << endl;
        if (a[i] - b[i]==0){
            t++;
            //cout << i << endl;
        }
        else {
            res = max(res, t);
            t = 0;
        }
    }
    cout << 1ll*res*res+1ll*2*res << endl;
    return 0;
}

 

B-SHTMYCBDFTT

直接模拟就好了，O(n)，注意取模

#include<iostream>
#include<stack>
#include<cstdio>
#include<cmath>
#include<queue>
#include<cstring>
#include<string>
#include<algorithm>
using namespace std;
typedef long long ll;
const int maxn = 3e5+10;
const int inf = 0x7fffffff;
const int mod = 100000007;
//==========================
ll a[maxn];
int n;
int main()
{
    ios::sync_with_stdio(false);
    cin >> n;
    ll ans1 = 0,ans2=0;
    for (int i = 0; i < n; i++){
        cin >> a[i];
        ans1 ^= a[i];
        ans2 += a[i];
        ans2 %= mod;
    }
    cout << (ans1 + ans2)%mod << endl;
    return 0;
}