题意:给定 n 个文本串,m个病毒串,文本串重叠部分可以合并,但合并后不能含有病毒串,问所有文本串合并后最短多长。
析:先把所有的文本串和病毒都插入到AC自动机上,不过标记不一样,可以给病毒标记-1,如果访问知道就知道不可行的,然后处理出两两串叠加的最小长度,这个要用bfs,在AC自动机上把这个处理出来,然后剩下的就是一个简单的DP了,dp[s][i] 表示状态为 s 时,i 串在后面,长度最短是多少。
代码如下:
#pragma comment(linker, "/STACK:1024000000,1024000000") #include <cstdio> #include <string> #include <cstdlib> #include <cmath> #include <iostream> #include <cstring> #include <set> #include <queue> #include <algorithm> #include <vector> #include <map> #include <cctype> #include <cmath> #include <stack> #include <sstream> #include <list> #include <assert.h> #include <bitset> #include <numeric> #define debug() puts("++++"); #define gcd(a, b) __gcd(a, b) #define lson l,m,rt<<1 #define rson m+1,r,rt<<1|1 #define fi first #define se second #define pb push_back #define sqr(x) ((x)*(x)) #define ms(a,b) memset(a, b, sizeof a) //#define sz size() #define pu push_up #define pd push_down #define cl clear() //#define all 1,n,1 #define FOR(i,x,n) for(int i = (x); i < (n); ++i) #define freopenr freopen("in.txt", "r", stdin) #define freopenw freopen("out.txt", "w", stdout) using namespace std; typedef long long LL; typedef unsigned long long ULL; typedef pair<LL, int> P; const int INF = 0x3f3f3f3f; const LL LNF = 1e17; const double inf = 1e20; const double PI = acos(-1.0); const double eps = 1e-8; const int maxn = 1e5 + 10; const int maxm = 1e6 + 5; const int mod = 10007; const int dr[] = {-1, 0, 1, 0}; const int dc[] = {0, -1, 0, 1}; const char *de[] = {"0000", "0001", "0010", "0011", "0100", "0101", "0110", "0111", "1000", "1001", "1010", "1011", "1100", "1101", "1110", "1111"}; int n, m; const int mon[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; const int monn[] = {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; inline bool is_in(int r, int c) { return r >= 0 && r < n && c >= 0 && c < m; } const int maxnode = 6e4 + 100; const int sigma = 2; int dist[15][15], last[15], cnt; struct Aho{ int ch[maxnode][sigma], f[maxnode]; int val[maxnode]; int sz; void clear(){ sz = 1; ms(ch[0], 0); } inline int idx(char ch){ return ch - '0'; } void insert(char *s, int v){ int u = 0; for(int i = 0; s[i]; ++i){ int c = idx(s[i]); if(!ch[u][c]){ ms(ch[sz], 0); val[sz] = 0; ch[u][c] = sz++; } u = ch[u][c]; } if(v > 0) val[u] |= 1<<v; else val[u] = v; } void getFail(){ queue<int> q; f[0] = 0; for(int c = 0; c < sigma; ++c){ int u = ch[0][c]; if(u){ q.push(u); f[u] = 0; } } while(!q.empty()){ int r = q.front(); q.pop(); for(int c = 0; c < sigma; ++c){ int u = ch[r][c]; if(!u){ ch[r][c] = ch[f[r]][c]; continue; } q.push(u); int v = f[r]; while(v && !ch[v][c]) v = f[v]; f[u] = ch[v][c]; if(val[u] > 0 && val[f[u]] > 0) val[u] |= val[f[u]]; } } } int d[maxnode]; void bfs(int s){ queue<int> q; ms(d, INF); d[last[s]] = 0; q.push(last[s]); while(!q.empty()){ int u = q.front(); q.pop(); for(int c = 0; c < sigma; ++c){ int nxt = ch[u][c]; if(d[nxt] > d[u] + 1 && val[nxt] >= 0){ d[nxt] = d[u] + 1; q.push(nxt); } } } for(int i = 0; i < cnt; ++i) dist[s][i] = d[last[i]]; } }; Aho aho; char s[500006]; int dp[2100][13]; int main(){ while(scanf("%d %d", &n, &m) == 2 && n+m){ aho.cl; for(int i = 1; i <= n; ++i){ scanf("%s", s); aho.insert(s, i); } for(int i = 0; i < m; ++i){ scanf("%s", s); aho.insert(s, -1); } aho.getFail(); cnt = 1; for(int i = 0; i < aho.sz; ++i) if(aho.val[i] > 0) last[cnt++] = i; for(int i = 0; i < cnt; ++i) aho.bfs(i); ms(dp, INF); dp[1][0] = 0; int all = 1<<cnt; FOR(i, 0, all) for(int j = 0; j < cnt; ++j){ if(dp[i][j] == INF) continue; for(int k = 0; k < cnt; ++k){ if(i&1<<k) continue; dp[i|1<<k][k] = min(dp[i|1<<k][k], dp[i][j] + dist[j][k]); } } int ans = INF; for(int i = 0; i < cnt; ++i) ans = min(ans, dp[all-1][i]); printf("%d\n", ans); } return 0; }