poj1743 后缀数组， poj挂了 存个代码

#include<bits/stdc++.h>
#define LL long long
#define fi first
#define se second
#define mk make_pair
#define pii pair<int, int>
#define y1 skldjfskldjg
#define y2 skldfjsklejg

using namespace std;

const int N = 1e5 + ;
const int M = 1e5 + ;
const int inf = 0x3f3f3f3f;
const LL INF = 0x3f3f3f3f3f3f3f3f;

int s[N], a[N], n;
int sa[N], t[N], t2[N], c[N], rk[N], height[N];

void buildSa(int *s, int n, int m) {
    int i, j = , k = , *x = t, *y = t2;
    for(i = ; i < m; i++) c[i] = ;
    for(i = ; i < n; i++) c[x[i] = s[i]]++;
    for(i = ; i < m; i++) c[i] += c[i - ];
    for(i = n - ; i >= ; i--) sa[--c[x[i]]] = i;
    for(int k = ; k <= n; k <<= ) {
        int p = ;
        for(i = n - k; i < n; i++) y[p++] = i;
        for(i = ; i < n; i++) if(sa[i] >= k) y[p++] = sa[i] - k;
        for(i = ; i < m; i++) c[i] = ;
        for(i = ; i < n; i++) c[x[y[i]]]++;
        for(i = ; i < m; i++) c[i] += c[i - ];
        for(i = n - ; i >= ; i--) sa[--c[x[y[i]]]] = y[i];
        swap(x, y);
        p = ; x[sa[]] = ;
        for(int i = ; i < n; i++) {
            if(y[sa[i - ]] == y[sa[i]] && y[sa[i - ] + k] == y[sa[i] + k])
                x[sa[i]] = p - ;
            else x[sa[i]] = p++;
        }
        if(p >= n) break;
        m = p;
     }

     for(i = ; i < n; i++) rk[sa[i]] = i;
     for(i = ; i < n - ; i++) {
        if(k) k--;
        j = sa[rk[i] - ];
        while(s[i + k] == s[j + k]) k++;
        height[rk[i]] = k;
     }
}

struct ST
{
    int dp[N][], mm[N], ty;
    void build(int n,int b[],int _ty)
    {
        ty=_ty;
        for(int i=-(mm[]=-);i<N;i++)
            mm[i]=mm[i-]+((i&(i-))==);
        for(int i=;i<=n;i++)
            dp[i][]=ty*b[i];
        for(int j=;j<=mm[n];j++)
            for(int i=;i+(<<j)-<=n;i++)
                dp[i][j]=max(dp[i][j-],dp[i+(<<(j-))][j-]);
    }
    int query(int x,int y)
    {
        int k=mm[y-x+];
        return ty*max(dp[x][k],dp[y-(<<k)+][k]);
    }
}rmqMx, rmqMn, rmq;

bool check(int len) {
    for(int i = , j = ; i < n; i++) {
        j = max(i, j);
        while(j < n && rmq.query(i + , j + ) >= len) j++;
        if(i != j) {
            int mx = rmqMx.query(i + , j);
            int mn = rmqMn.query(i + , j);

            if(mx > sa[i] + len) return true;
            if(sa[i] > mn + len) return true;
        }
    }
    return false;
}

int main() {
    while(scanf("%d", &n) != EOF && n) {

        for(int i = ; i < n; i++) {
            scanf("%d", &a[i]);
        }

        if(n < ) {
            puts("");
        } else {

            for(int i = ; i < n - ; i++) {
                s[i] = a[i + ] - a[i] + ;
            }
            n--; s[n] = ;

            buildSa(s, n + , );
            rmqMx.build(n, sa, );
            rmqMn.build(n, sa, -);
            rmq.build(n, height, -);

            int l = , r = n / , mid, ans = -;

            while(l <= r) {
                mid = l + r >> ;
                if(check(mid)) ans = mid, l = mid + ;
                else r = mid - ;
            }

            if(ans == -) puts("");
            else printf("%d\n", ans + );
        }
    }
    return ;
}

/*
3 1000000000
100000 1000000000

507109376
*/