str2int HDU

题意:

给出 n 个串,求出这 n 个串所有子串代表的数字的和。

题解;

首先可以把这些串构建后缀自动机(sam.last=1就好了),

因为后缀自动机上从 root走到的任意节点都是一个子串,所有可以利用这个性质来做

我们发现对于dp[u]−>dp[v]过程,如果之前走到 dp[u] 的有 12,2 两步,假设现在往 3 这条边走,

得到 1210+3,210+3,那么其实这些值的贡献是可以一次性计算的,无论之前走到 dp[u] 的有几条路,都需要让他们全部 10,而 3 的贡献则是由走到 dp[u] 的路径数确定的。

那么我们就可以得到第二个方程:

  1. dp1[i] 表示节点 的贡献
  2. dp2[i] 表示之前有多少种方案走到 i
  3. dp1[v]=dp1[v]+dp1[u]10+dp2[u]j
  4. dp2[v]=dp[2[v]+dp2[v]
  1 #include <set>
  2 #include <map>
  3 #include <stack>
  4 #include <queue>
  5 #include <cmath>
  6 #include <ctime>
  7 #include <cstdio>
  8 #include <string>
  9 #include <vector>
 10 #include <cstring>
 11 #include <iostream>
 12 #include <algorithm>
 13 #include <unordered_map>
 14 
 15 #define  pi    acos(-1.0)
 16 #define  eps   1e-9
 17 #define  fi    first
 18 #define  se    second
 19 #define  rtl   rt<<1
 20 #define  rtr   rt<<1|1
 21 #define  bug                printf("******
")
 22 #define  mem(a, b)          memset(a,b,sizeof(a))
 23 #define  name2str(x)        #x
 24 #define  fuck(x)            cout<<#x" = "<<x<<endl
 25 #define  sfi(a)             scanf("%d", &a)
 26 #define  sffi(a, b)         scanf("%d %d", &a, &b)
 27 #define  sfffi(a, b, c)     scanf("%d %d %d", &a, &b, &c)
 28 #define  sffffi(a, b, c, d) scanf("%d %d %d %d", &a, &b, &c, &d)
 29 #define  sfL(a)             scanf("%lld", &a)
 30 #define  sffL(a, b)         scanf("%lld %lld", &a, &b)
 31 #define  sfffL(a, b, c)     scanf("%lld %lld %lld", &a, &b, &c)
 32 #define  sffffL(a, b, c, d) scanf("%lld %lld %lld %lld", &a, &b, &c, &d)
 33 #define  sfs(a)             scanf("%s", a)
 34 #define  sffs(a, b)         scanf("%s %s", a, b)
 35 #define  sfffs(a, b, c)     scanf("%s %s %s", a, b, c)
 36 #define  sffffs(a, b, c, d) scanf("%s %s %s %s", a, b,c, d)
 37 #define  FIN                freopen("../in.txt","r",stdin)
 38 #define  gcd(a, b)          __gcd(a,b)
 39 #define  lowbit(x)          x&-x
 40 #define  IO                 iOS::sync_with_stdio(false)
 41 
 42 
 43 using namespace std;
 44 typedef long long LL;
 45 typedef unsigned long long ULL;
 46 const ULL seed = 13331;
 47 const LL INFLL = 0x3f3f3f3f3f3f3f3fLL;
 48 const int maxm = 8e6 + 10;
 49 const int INF = 0x3f3f3f3f;
 50 const int mod = 2012;
 51 const int maxn = 1e6 + 7;
 52 
 53 struct Suffix_Automaton {
 54     int last, tot, nxt[maxn << 1][26], fail[maxn << 1];//last是未加入此字符前最长的前缀(整个串)所属的节点的编号
 55     int len[maxn << 1];// 最长子串的长度 (该节点子串数量 = len[x] - len[fa[x]])
 56     int sz[maxn << 1];// 被后缀链接的个数,方便求节点字符串的个数
 57     LL num[maxn << 1];// 该状态子串的数量
 58     LL maxx[maxn << 1];// 长度为x的子串出现次数最多的子串的数目
 59     LL sum[maxn << 1];// 该节点后面所形成的自字符串的总数
 60     LL subnum, sublen;// subnum表示不同字符串数目,sublen表示不同字符串总长度
 61     int X[maxn << 1], Y[maxn << 1]; // Y表示排名为x的节点,X表示该长度前面还有多少个
 62     int minn[maxn << 1], mx[maxn << 1];//minn[i]表示多个串在后缀自动机i节点最长公共子串,mx[i]表示单个串的最长公共子串
 63     void init() {
 64         tot = last = 1;
 65         fail[1] = len[1] = 0;
 66         for (int i = 0; i < 26; i++) nxt[1][i] = 0;
 67     }
 68 
 69     void extend(int c) {
 70         int u = ++tot, v = last;
 71         for (int i = 0; i <= 25; i++) nxt[u][i] = 0;
 72         fail[u] = 0;
 73         len[u] = len[v] + 1;
 74         num[u] = 1;
 75         for (; v && !nxt[v][c]; v = fail[v]) nxt[v][c] = u;
 76         if (!v) fail[u] = 1, sz[1]++;
 77         else if (len[nxt[v][c]] == len[v] + 1) fail[u] = nxt[v][c], sz[nxt[v][c]]++;
 78         else {
 79             int now = ++tot, cur = nxt[v][c];
 80             len[now] = len[v] + 1;
 81             memcpy(nxt[now], nxt[cur], sizeof(nxt[cur]));
 82             fail[now] = fail[cur];
 83             fail[cur] = fail[u] = now;
 84             for (; v && nxt[v][c] == cur; v = fail[v]) nxt[v][c] = now;
 85         }
 86         last = u;
 87         //return len[last] - len[fail[last]];//多添加一个子串所产生不同子串的个数
 88     }
 89 
 90     void get_num() {// 每个节点子串出现的次数
 91         for (int i = 1; i <= tot; i++) X[i] = 0;
 92         for (int i = 1; i <= tot; i++) X[len[i]]++;
 93         for (int i = 1; i <= tot; i++) X[i] += X[i - 1];
 94         for (int i = 1; i <= tot; i++) Y[X[len[i]]--] = i;
 95         for (int i = tot; i >= 1; i--) num[fail[Y[i]]] += num[Y[i]];
 96     }
 97 
 98     void get_maxx(int n) {// 长度为x的子串出现次数最多的子串的数目
 99         get_num();
100         for (int i = 1; i <= tot; i++) maxx[len[i]] = max(maxx[len[i]], num[i]);
101     }
102 
103     void get_sum() {// 该节点后面所形成的自字符串的总数
104         get_num();
105         for (int i = tot; i >= 1; i--) {
106             sum[Y[i]] = 1;
107             for (int j = 0; j <= 25; j++)
108                 sum[Y[i]] += sum[nxt[Y[i]][j]];
109         }
110     }
111 
112     void get_subnum() {//本质不同的子串的个数
113         subnum = 0;
114         for (int i = 1; i <= tot; i++) subnum += len[i] - len[fail[i]];
115     }
116 
117     void get_sublen() {//本质不同的子串的总长度
118         sublen = 0;
119         for (int i = 1; i <= tot; i++) sublen += 1LL * (len[i] + len[fail[i]] + 1) * (len[i] - len[fail[i]]) / 2;
120     }
121 
122     void get_sa() { // Y表示排名为x的节点,X表示该长度前面还有多少个
123         for (int i = 0; i <= tot; i++) X[i] = 0;
124         for (int i = 1; i <= tot; i++) X[len[i]]++;
125         for (int i = 1; i <= tot; i++) X[i] += X[i - 1];
126         for (int i = 1; i <= tot; i++) Y[X[len[i]]--] = i;
127     }
128 
129     void match(char s[]) {//多个串的最长公共子串
130         mem(mx, 0);
131         int n = strlen(s), p = 1, maxlen = 0;
132         for (int i = 0; i < n; i++) {
133             int c = s[i] - 'a';
134             if (nxt[p][c]) p = nxt[p][c], maxlen++;
135             else {
136                 for (; p && !nxt[p][c]; p = fail[p]);
137                 if (!p) p = 1, maxlen = 0;
138                 else maxlen = len[p] + 1, p = nxt[p][c];
139             }
140             mx[p] = max(mx[p], maxlen);
141         }
142         for (int i = tot; i; i--)
143             mx[fail[i]] = max(mx[fail[i]], min(len[fail[i]], mx[i]));
144         for (int i = tot; i; i--)
145             if (minn[i] == -1 || minn[i] > maxx[i]) minn[i] = mx[i];
146     }
147 
148     void get_kth(int k) {//求出字典序第K的子串
149         int pos = 1, cnt;
150         string s = "";
151         while (k) {
152             for (int i = 0; i <= 25; i++) {
153                 if (nxt[pos][i] && k) {
154                     cnt = nxt[pos][i];
155                     if (sum[cnt] < k) k -= sum[cnt];
156                     else {
157                         k--;
158                         pos = cnt;
159                         s += (char) (i + 'a');
160                         break;
161                     }
162                 }
163             }
164         }
165         cout << s << endl;
166     }
167 
168     int dp1[maxn << 1], dp2[maxn << 1];
169 
170     void solve() {
171         get_sa();
172         mem(dp1, 0), mem(dp2, 0);
173         dp2[1] = 1;
174         int ans = 0;
175         for (int i = 1; i <= tot; i++) {
176             int u = Y[i];
177             ans = (ans + dp1[u]) % mod;
178             for (int j = (u == 1 ? 1 : 0); j <= 9; j++) {
179                 if (!nxt[u][j + 1]) continue;
180                 int idx = nxt[u][j + 1];
181                 dp1[idx] = (dp1[idx] + dp1[u] * 10 + j * dp2[u]) % mod;
182                 dp2[idx] = (dp2[idx] + dp2[u]) % mod;
183             }
184         }
185         printf("%d
", ans);
186     }
187 } sam;
188 
189 int T;
190 char s[maxn];
191 
192 int main() {
193 #ifndef ONLINE_JUDGE
194     FIN;
195 #endif
196     while (~sfi(T)) {
197         sam.init();
198         while (T--) {
199             sam.last = 1;
200             sfs(s + 1);
201             int len = strlen(s + 1);
202             for (int i = 1; i <= len; i++) sam.extend((s[i] - '0' + 1));
203         }
204         sam.solve();
205     }
206 #ifndef ONLINE_JUDGE
207     cout << "Totle Time : " << (double) clock() / CLOCKS_PER_SEC << "s" << endl;
208 #endif
209     return 0;
210 }
View Code
原文地址:https://www.cnblogs.com/qldabiaoge/p/11571630.html