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#include <bits/stdc++.h>
namespace IO {
inline char read() {
static const int IN_LEN = 1000000;
static char buf[IN_LEN], *s, *t;
s == t ? t = (s = buf) + fread(buf, 1, IN_LEN, stdin) : 0;
return s == t ? -1 : *s++;
}
template <typename T>
inline void read(T &x) {
static char c;
static bool iosig;
for (iosig = false, c = read(); !isdigit(c); c = read()) {
if (c == -1) return;
c == '-' ? iosig = true : 0;
}
for (x = 0; isdigit(c); c = read()) x = x * 10 + (c ^ '0');
iosig ? x = -x : 0;
}
inline int read(char *buf) {
register int s = 0;
register char c;
while (c = read(), isspace(c) && c != -1)
;
if (c == -1) {
*buf = 0;
return -1;
}
do
buf[s++] = c;
while (c = read(), !isspace(c) && c != -1);
buf[s] = 0;
return s;
}
const int OUT_LEN = 10000000;
char obuf[OUT_LEN], *oh = obuf;
inline void print(char c) {
oh == obuf + OUT_LEN ? (fwrite(obuf, 1, OUT_LEN, stdout), oh = obuf) : 0;
*oh++ = c;
}
template <typename T>
inline void print(T x) {
static int buf[30], cnt;
if (x == 0) {
print('0');
} else {
x < 0 ? (print('-'), x = -x) : 0;
for (cnt = 0; x; x /= 10) buf[++cnt] = x % 10 | 48;
while (cnt) print((char)buf[cnt--]);
}
}
inline void print(const char *s) {
for (; *s; s++) print(*s);
}
inline void flush() { fwrite(obuf, 1, oh - obuf, stdout); }
struct InputOutputStream {
template <typename T>
inline InputOutputStream &operator>>(T &x) {
read(x);
return *this;
}
template <typename T>
inline InputOutputStream &operator<<(const T &x) {
print(x);
return *this;
}
~InputOutputStream() { flush(); }
} io;
}
namespace {
#define long long long
using IO::io;
const int MAXN = 3000;
int n, m;
int a[MAXN + 1], sum[MAXN + 1];
int f[MAXN + 1], g[MAXN + 1];
inline double slope(const int a, const int b) {
return (double)(g[a] - g[b] + sum[a] * sum[a] - sum[b] * sum[b]) /
(double)(sum[a] - sum[b]);
}
inline void solve() {
io >> n >> m;
for (register int i = 1; i <= n; i++) io >> a[i];
for (register int i = 1; i <= n; i++) sum[i] = sum[i - 1] + a[i];
memset(f + 1, 0x3f, sizeof(int) * n);
for (register int j = 1; j <= m; j++) {
memcpy(g, f, sizeof(f));
memset(f, 0, sizeof(f));
static int q[MAXN + 1];
register int *l = q, *r = q;
*r = 0;
for (register int i = 1; i <= n; i++) {
while (l < r && slope(*(l + 1), *l) < 2 * sum[i]) l++;
f[i] = g[*l] + (sum[i] - sum[*l]) * (sum[i] - sum[*l]);
while (l < r && slope(*r, *(r - 1)) > slope(*r, i)) r--;
*++r = i;
}
}
io << f[n] * m - sum[n] * sum[n];
}
#undef long
}
int main() {
solve();
return 0;
}
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