Init

ACMOJ-2080.cpp

@@ -0,0 +1,193 @@
+#include <bits/stdc++.h>
+#define unlikely(x) __builtin_expect(!!(x), 0)
+struct char_reader {
+  FILE *f;
+  char *buf, *p1, *p2;
+  int size;
+  char_reader(FILE *fin, int bufsize = 1 << 16) {
+    f = fin;
+    size = bufsize;
+    p1 = p2 = 0;
+    buf = new char[size];
+  }
+  ~char_reader() { delete[] buf; }
+  inline int operator()() {
+    return p1 == p2 && (p2 = (p1 = buf) + fread(buf, 1, size, f), p1 == p2)
+               ? EOF
+               : *p1++;
+  }
+};
+struct char_writer {
+  FILE *f;
+  char *buf, *p, *end;
+  int size;
+  char_writer(FILE *fout, int bufsize = 1 << 16) {
+    f = fout;
+    size = bufsize;
+    buf = new char[size];
+    p = buf;
+    end = buf + bufsize;
+  }
+  ~char_writer() {
+    fwrite(buf, p - buf, 1, f);
+    delete[] buf;
+  }
+  inline char operator()(char ch) {
+    if (unlikely(end == p)) {
+      fwrite(buf, end - buf, 1, f);
+      p = buf;
+    }
+    return *p++ = ch;
+  }
+};
+char_reader gch(stdin);
+char_writer wch(stdout);
+template <typename T>
+inline int read(T &t) {
+  bool f = false;
+  int ch;
+  while (ch = gch(), !((ch >= '0' && ch <= '9') || ch == '-')) {
+    if (ch == EOF) return 0;
+  }
+  t = 0;
+  if (ch == '-') f = true, ch = gch();
+  t = ch ^ 48;
+  while (ch = gch(), ch >= '0' && ch <= '9')
+    t = (t << 3) + (t << 1) + (ch ^ 48);
+  if (f) t = -t;
+  return 1;
+}
+inline int read(char &c) {
+  c = 0;
+  int ch;
+  while (ch = gch(), (ch == ' ' || ch == '\n' || ch == '\r' || ch == '\t')) {
+    if (ch == EOF) return 0;
+  }
+  c = ch;
+  return 1;
+}
+inline int read(char *s) {
+  int ch;
+  while (ch = gch(), (ch == ' ' || ch == '\n' || ch == '\r' || ch == '\t')) {
+    if (ch == EOF) return 0;
+  }
+  *s++ = ch;
+  while (ch = gch(),
+         !(ch == ' ' || ch == '\n' || ch == '\r' || ch == '\t') && ch != EOF)
+    *s++ = ch;
+  *s++ = 0;
+  return 1;
+}
+inline int read(const char *s) { return read((char *)s); }
+inline int readline(char *s) {
+  int ch;
+  while (ch = gch(), (ch == ' ' || ch == '\n' || ch == '\r' || ch == '\t')) {
+    if (ch == EOF) return 0;
+  }
+  *s++ = ch;
+  while (ch = gch(), !(ch == '\n' || ch == '\r') && ch != EOF) *s++ = ch;
+  *s++ = 0;
+  return 1;
+}
+inline int readline(const char *s) { return readline((char *)s); }
+template <typename T>
+inline void write(T t) {
+  int stk[20], cnt = 0;
+  if (t == 0) {
+    wch('0');
+    return;
+  }
+  if (t < 0) {
+    wch('-');
+    t = -t;
+  }
+  while (t > 0) {
+    stk[cnt++] = t % 10;
+    t /= 10;
+  }
+  while (cnt) wch(stk[--cnt] + '0');
+}
+inline void write(char t) { wch(t); }
+inline void write(char *s) {
+  while (*s) wch(*s++);
+}
+inline void write(const char *s) { write((char *)s); }
+#if __cplusplus >= 201103L
+template <typename T, typename... Args>
+inline int read(T &t, Args &...args) {
+  return read(t) + read(args...);
+}
+template <typename T, typename... Args>
+inline void write(T t, Args... args) {
+  write(t);
+  write(args...);
+}
+#else
+template <typename A_t, typename B_t>
+inline int read(A_t &a, B_t &b) {
+  return read(a) + read(b);
+}
+template <typename A_t, typename B_t, typename C_t>
+inline int read(A_t &a, B_t &b, C_t &c) {
+  return read(a) + read(b) + read(c);
+}
+template <typename A_t, typename B_t, typename C_t, typename D_t>
+inline int read(A_t &a, B_t &b, C_t &c, D_t &d) {
+  return read(a) + read(b) + read(c) + read(d);
+}
+template <typename A_t, typename B_t>
+inline void write(A_t a, B_t b) {
+  write(a);
+  write(b);
+}
+template <typename A_t, typename B_t, typename C_t>
+inline void write(A_t a, B_t b, C_t c) {
+  write(a);
+  write(b);
+  write(c);
+}
+template <typename A_t, typename B_t, typename C_t, typename D_t>
+inline void write(A_t a, B_t b, C_t c, D_t d) {
+  write(a);
+  write(b);
+  write(c);
+  write(d);
+}
+#endif
+using namespace std;
+typedef long long LL;
+const int N = 100005, K = 25;
+const LL inf = LONG_LONG_MAX;
+int n, k;
+LL a[N], f[K][N], t[N], lc = 1, rc, res;
+void add(int x) { res += t[a[x]]++; }
+void del(int x) { res -= --t[a[x]]; }
+LL calc(int l, int r) {
+  while (lc > l) add(--lc);
+  while (rc < r) add(++rc);
+  while (lc < l) del(lc++);
+  while (rc > r) del(rc--);
+  return res;
+}
+void solve(int l, int r, int L, int R, LL k) {
+  if (l > r) return;
+  int mid = (l + r) >> 1, tmp = L;
+  LL mi = inf;
+  for (int i = min(mid - 1, R); i >= L; --i)
+    if (f[k - 1][i] + calc(i + 1, mid) < mi)
+      mi = f[k - 1][i] + calc(i + 1, mid), tmp = i;
+  f[k][mid] = mi;
+  solve(l, mid - 1, L, tmp, k);
+  solve(mid + 1, r, tmp, R, k);
+}
+int main() {
+#ifdef local
+  freopen("pro.in", "r", stdin);
+#endif
+  read(n, k);
+  for (int i = 1; i <= n; ++i) read(a[i]);
+  solve(1, n, 0, 0, 1);
+  for (int i = 2; i <= k; ++i) solve(1, n, 0, n - 1, i);
+  write(f[k][n], '\n');
+  return 0;
+}