POJ 3729 Facer’s string

#include <iostream>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <bitset>
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <climits>
#include <cstdlib>
#include <cmath>
#include <time.h>
#define maxn 100005
#define maxm 400005
#define eps 1e-10
#define mod 1000000007
#define INF 0x3f3f3f3f
#define PI (acos(-1.0))
#define lowbit(x) (x&(-x))
#define mp make_pair
#define ls o<<1
#define rs o<<1 | 1
#define lson o<<1, L, mid
#define rson o<<1 | 1, mid+1, R
//#pragma comment(linker, "/STACK:16777216")
typedef long long LL;
typedef unsigned long long ULL;
//typedef int LL;
using namespace std;
LL qpow(LL a, LL b){LL res=1,base=a;while(b){if(b%2)res=res*base;base=base*base;b/=2;}return res;}
LL powmod(LL a, LL b){LL res=1,base=a;while(b){if(b%2)res=res*base%mod;base=base*base%mod;b/=2;}return res;}
// head

int c[maxn];
int s[maxn], t1[maxn], t2[maxn], sa[maxn];
int rank[maxn], height[maxn];

void build(int n, int m)
{
int *x = t1, *y = t2;
for(int i = 0; i < m; i++) c[i] = 0;
for(int i = 0; i < n; i++) c[x[i] = s[i]]++;
for(int i = 1; i < m; i++) c[i] += c[i-1];
for(int i = n-1; i >= 0; i--) sa[--c[x[i]]] = i;
for(int k = 1; k <= n; k <<= 1) {
int p = 0;
for(int i = n - k; i < n; i++) y[p++] = i;
for(int i = 0; i < n; i++) if(sa[i] >= k) y[p++] = sa[i] - k;
for(int i = 0; i < m; i++) c[i] = 0;
for(int i = 0; i < n; i++) c[x[y[i]]]++;
for(int i = 1; i < m; i++) c[i] += c[i-1];
for(int i = n-1; i >= 0; i--) sa[--c[x[y[i]]]] = y[i];
p = 1, swap(x, y), x[sa[0]] = 0;
for(int i = 1; i < n; i++)
x[sa[i]] = y[sa[i]] == y[sa[i-1]] && y[sa[i]+k] == y[sa[i-1]+k] ? p-1 : p++;
if(p >= n) break;
m = p;
}
}

void getheight(int n)
{
int k = 0;
for(int i = 0; i <= n; i++) rank[sa[i]] = i;
for(int i = 0; i < n; i++) {
if(k) k--;
int j = sa[rank[i] - 1];
while(s[i+k] == s[j+k]) k++;
height[rank[i]] = k;
}
}

int n, m, k, len;

void read(void)
{
for(int i = 0; i < n; i++) scanf("%d", &s[i]), s[i] += 2;
s
= 0;
for(int i = n+1; i <= n + m; i++) scanf("%d", &s[i]), s[i] += 2;
len = n + m + 1;
s[len] = 1;
}

void work(void)
{
build(len + 1, 10005);
getheight(len);
int t1 = 0, t2 = 0, flag = 0;
int ans = 0, res = 0;
for(int i = 1; i <= len; i++) {
if(height[i] < k) {
if(t2) ans += t1;
t1 = t2 = flag = 0;
}
else {
if(!flag) {
if(sa[i-1] < n) t1++;
else t2++;
flag = 1;
}
if(sa[i] < n) t1++;
else t2++;
}
}
if(t2) ans += t1;
t1 = t2 = flag = 0;
for(int i = 1; i <= len; i++) {
if(height[i] < k + 1) {
if(t2) res += t1;
t1 = t2 = flag = 0;
}
else {
if(!flag) {
if(sa[i-1] < n) t1++;
else t2++;
flag = 1;
}
if(sa[i] < n) t1++;
else t2++;
}
}
if(t2) res += t1;
printf("%d\n", ans - res);
}

int main(void)
{
while(scanf("%d%d%d", &n, &m, &k)!=EOF) {
read();
work();
}

return 0;
}