2018 Nowcoder Multi-University Training Contest 10

Posted 2022-02-27 dup4

Practice Link

J. Rikka with Nickname

题意：
给出\(n\)个字符串，要求依次合并两个串\(s, t\)，满足将\(t\)合并到\(s\)中变成\(r\)，使得\(s\)是\(r\)的前缀，并且\(t\)是\(r\)的一个子序列。

思路：
动态维护序列自动机，贪心插入即可。

代码：

#include <bits/stdc++.h>
using namespace std;
 
#define N 1000010
char s[N], res[N];
int nx[N][26];
int n, m, len;
 
void add(int now) 
    for (int i = now; i <= len; ++i) 
        res[++m] = s[i];
        for (int j = m - 1; j >= 0; --j) 
            nx[j][res[m] - 'a'] = m;
            if (res[j] == s[i]) 
                break;
            
        
    

 
int main() 
    int T; scanf("%d", &T);
    while (T--) 
        m = 0;
        memset(nx, -1, sizeof nx);
        scanf("%d", &n);
        for (int i = 1; i <= n; ++i) 
            scanf("%s", s + 1);
            len = strlen(s + 1);
            if (i == 1) 
                add(1);
             else 
                int now = 0;
                for (int j = 1; j <= len; ++j) 
                    now = nx[now][s[j] - 'a'];
                    if (now == -1) 
                        add(j);
                        break;
                    
                
            
        
        res[m + 1] = 0;
        printf("%s\n", res + 1);
    
    return 0;