BZOJ1461 字符串的匹配

  1 /**************************************************************
  2     Problem: 1461
  3     User: rausen
  4     Language: C++
  5     Result: Accepted
  6     Time:644 ms
  7     Memory:12564 kb
  8 ****************************************************************/
  9  
 10 #include <cstdio>
 11 #include <cstring>
 12  
 13 #define lowbit(x) x & -x
 14 using namespace std;
 15 const int S = 10005;
 16 const int N = 500005;
 17 int a[N], b[N], les[N], equ[N], next[N], ans[N];
 18 int BIT[S];
 19 int n, m, s, tot;
 20  
 21 inline int read(){
 22     int x = 0, sgn = 1;
 23     char ch = getchar();
 24     while (ch < ‘0‘ || ch > ‘9‘){
 25         if (ch == ‘-‘) sgn = -1;
 26         ch = getchar();
 27     }
 28     while (ch >= ‘0‘ && ch <= ‘9‘){
 29         x = x * 10 + ch - ‘0‘;
 30         ch = getchar();
 31     }
 32     return sgn * x;
 33 }
 34  
 35 inline void add(int x, int del){
 36     while (x <= s)
 37         BIT[x] += del, x += lowbit(x);
 38 }
 39  
 40 inline int query(int x){
 41     int res = 0;
 42     while (x)
 43         res += BIT[x], x -= lowbit(x);
 44     return res;
 45 }
 46  
 47 void get_next(){
 48     memset(BIT, 0, sizeof(BIT));
 49     next[1] = 0;
 50     int i = 2, j = 0, k;
 51     for (; i <= m; ++i){
 52         add(b[i], 1);
 53         while (j && (query(b[i] - 1) != les[j + 1] || query(b[i]) != equ[j + 1])){
 54             for (k = i - j; k < i - next[j]; ++k)
 55                 add(b[k], -1);
 56             j = next[j];
 57         }
 58         next[i] = ++j;
 59     }
 60 }
 61  
 62 void kmp(){
 63     memset(BIT, 0, sizeof(BIT));
 64     int i = 1, j = 0, k, res = 0;
 65     for (; i <= n; ++i){
 66         add(a[i], 1);
 67         while (j && (query(a[i] - 1) != les[j + 1] || query(a[i]) != equ[j + 1])){
 68             for (k = i - j; k < i - next[j]; ++k)
 69                 add(a[k], -1);
 70             j = next[j];
 71         }
 72         if (j == m - 1){
 73             ans[++tot] = i - j;
 74             for (k = i - j; k < i - next[j]; ++k)
 75                 add(a[k], -1);
 76             j = next[j];
 77         }
 78         ++j;
 79     }
 80 }
 81  
 82 int main(){
 83     int i;
 84     n = read(), m = read(), s = read();
 85     for (i = 1; i <= n; ++i)
 86         a[i] = read();
 87     for (i = 1; i <= m; ++i)
 88         b[i] = read();
 89     memset(BIT, 0, sizeof(BIT));
 90     for (i = 1; i <= m; ++i){
 91         add(b[i], 1);
 92         les[i] = query(b[i] - 1);
 93         equ[i] = query(b[i]);
 94     }
 95     get_next();
 96     kmp();
 97     printf("%d\n", tot);
 98     for (i = 1; i <= tot; ++i)
 99         printf("%d\n", ans[i]);
100     return 0;
101 }