SPOJ New Distinct Substrings（后缀数组）

Given a string, we need to find the total number of its distinct substrings.

Input

T- number of test cases. T<=20; Each test case consists of one string, whose length is <= 50000

Output

For each test case output one number saying the number of distinct substrings.

Example

Input:
2
CCCCC
ABABA

Output:
5
9

题意：给你一个字符串，问你他所有子串中，有多少种不同的。
一个字符串任意一个后缀的前缀都是字符串的子串，所有的后缀的所有前缀，就是字符串的所有子串。

这样我们要求有多少种不同的子串，就可以用子串的总数减去重复子串的个数。

比如第二个样例，按排名把所有后缀排一下：

A

ABA

ABABA

BA

BABA

第一个后缀前面没有后缀了，所以不会与前面的重复，对于第二个后缀，重复的子串就是A，第三个后缀，与前面重复的子串就是A，AB，ABA，可以发现这就是最长公共前缀的长度，也就是height数组的值。

所以最后的答案就是 所有子串的总数 n*（n+1）/ 2 - sigma（heght[i]）

#include <cstdio>
#include <cstring>
#include<iostream>
#include <algorithm>
#define LL long long
using namespace std;

const int MAXN = 50010;

int SA[MAXN], Rank[MAXN], Height[MAXN], tax[MAXN], tp[MAXN], a[MAXN], n, m;
char str[MAXN];

void RSort()
{
for (int i = 0; i <= m; i ++) tax[i] = 0;
for (int i = 1; i <= n; i ++) tax[Rank[tp[i]]] ++;
for (int i = 1; i <= m; i ++) tax[i] += tax[i-1];
for (int i = n; i >= 1; i --) SA[tax[Rank[tp[i]]] --] = tp[i];
}
int cmp(int *f, int x, int y, int w) { return f[x] == f[y] && f[x + w] == f[y + w]; }

void Suffix()
{
for (int i = 1; i <= n; i ++) Rank[i] = a[i], tp[i] = i;
m = 156 ,RSort();

for (int w = 1, p = 1, i; p < n; w += w, m = p)
{
for (p = 0, i = n - w + 1; i <= n; i ++) tp[++ p] = i;
for (i = 1; i <= n; i ++) if (SA[i] > w) tp[++ p] = SA[i] - w;

RSort(), swap(Rank, tp), Rank[SA[1]] = p = 1;

for (i = 2; i <= n; i ++) Rank[SA[i]] = cmp(tp, SA[i], SA[i - 1], w) ? p : ++ p;
}

int j, k = 0;
for(int i = 1; i <= n; Height[Rank[i ++]] = k)
for( k = k ? k - 1 : k, j = SA[Rank[i] - 1]; a[i + k] == a[j + k]; ++ k);
}

void Init()
{
n = strlen(str+1);
for(int i=1;i<=n;i++)
a[i] = str[i];
Suffix();
}
int k;

int main(void)
{
int T,i,j;
scanf("%d",&T);
while(T--)
{
scanf("%s",str+1);
Init();
LL ans = (LL)n*(n+1)/2;
for(i=2;i<=n;i++)
ans -= Height[i];
printf("%lld\n",ans);
}

return 0;
}

Given a string, we need to find the total number of its distinct substrings.

Input

T- number of test cases. T<=20; Each test case consists of one string, whose length is <= 50000

Output

For each test case output one number saying the number of distinct substrings.

Example

Input:
2
CCCCC
ABABA

Output:
5
9