Update sa.cc

string/sa.cc

@@ -1,39 +1,28 @@
-#include <algorithm>
-#include <cstdio>
-#include <cstring>
-#include <iostream>
+#include "../include.hh"
 
-using namespace std;
-
-const int N = 1000010;
+constexpr int N = 1e6 + 10;
 
 char s[N];
-// key1[i] = rk[id[i]]（作为基数排序的第一关键字数组）
 int n, sa[N], rk[N], oldrk[N << 1], id[N], key1[N], cnt[N], height[N];
 
 bool cmp(int x, int y, int w) {
   return oldrk[x] == oldrk[y] && oldrk[x + w] == oldrk[y + w];
 }
 
-int main() {
-  int i, m = 127, p, w;
-
-  scanf("%s", s + 1);
+void calc_sa() {
     n = strlen(s + 1);
-
-  // calc sa[]
+    int i, m = 127, p, w;
     for (i = 1; i <= n; ++i) ++cnt[rk[i] = s[i]];
       for (i = 1; i <= m; ++i) cnt[i] += cnt[i - 1];
       for (i = n; i >= 1; --i) sa[cnt[rk[i]]--] = i;
 
-  for (w = 1;; w <<= 1, m = p) {  // m=p 就是优化计数排序值域
+      for (w = 1;; w <<= 1, m = p) {
         for (p = 0, i = n; i > n - w; --i) id[++p] = i;
         for (i = 1; i <= n; ++i)
           if (sa[i] > w) id[++p] = sa[i] - w;
 
         memset(cnt, 0, sizeof(cnt));
         for (i = 1; i <= n; ++i) ++cnt[key1[i] = rk[id[i]]];
-    // 注意这里px[i] != i，因为rk没有更新，是上一轮的排名数组
 
         for (i = 1; i <= m; ++i) cnt[i] += cnt[i - 1];
         for (i = n; i >= 1; --i) sa[cnt[key1[i]]--] = id[i];
@@ -44,16 +33,11 @@ int main() {
           break;
         }
       }
-
-  // calc height[]
-  for (i = 1, k = 0; i <= n; ++i) {
-    if (rk[i] == 0) continue;
-    if (k) --k;
-    while (s[i + k] == s[sa[rk[i] - 1] + k]) ++k;
-    height[rk[i]] = k;
 }
 
-  for (i = 1; i <= n; ++i) printf("%d ", sa[i]);
-
-  return 0;
+int main() {
+    untie;
+    cin >> (s + 1);  // array s starts from index 1
+    calc_sa();
+    for (int i = 1; i <= n; ++i) cout << sa[i] << " \n"[i == n];
 }