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| #pragma region revive
#include <set>
#include <map>
#include <cmath>
#include <queue>
#include <stack>
#include <bitset>
#include <cstdio>
#include <vector>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <iostream>
#include <algorithm>
#include <unordered_map>
#define inl inline
#define re register int
#define fa(x) t[x].fa
#define son(x,y) t[x].child[y]
#define ls(x) t[x].child[0]
#define rs(x) t[x].child[1]
#define ll long long
const int inf = 0x3f3f3f3f;
#define lowbit(x) ((x) & (-x))
using namespace std;
#ifndef _DEBUG
#define getchar() (*(IOB.in.p++))
#define putchar(c) (*(IOB.out.p++)=(c))
#define io_eof() (IOB.in.p>=IOB.in.pend)
struct IOBUF { struct { char buff[1 << 26], *p, *pend; }in; struct { char buff[1 << 26], *p; }out; IOBUF() { in.p = in.buff; out.p = out.buff; in.pend = in.buff + fread(in.buff, 1, 1 << 26, stdin); }~IOBUF() { fwrite(out.buff, 1, out.p - out.buff, stdout); } }IOB;
#endif
template<typename IO>
inl void write(IO x) {
if (x == 0) return (void)putchar('0');
if (x < 0)putchar('-'), x = -x;
static char buf[30];
char* p = buf;
while (x) {
*(p++) = x % 10 + '0';
x /= 10;
}
while (p > buf)putchar(*(--p));
}
inl void writestr(const char *s) { while (*s != 0)putchar(*(s++)); }
template<typename IO>inl void writeln(IO x) { write(x), putchar('\n'); }
template<typename IO>inl void writesp(IO x) { write(x), putchar(' '); }
inl int readstr(char *s) {
char *begin = s, c = getchar();
while (c < 33 || c>127) {
c = getchar();
}
while (c >= 33 && c <= 127) {
*(s++) = c;
c = getchar();
}
*s = 0;
return s - begin;
}
template<typename IO>
inl IO read() {
IO x = 0;
register bool w = 0;
register char c = getchar();
while (c > '9' || c < '0') {
if (c == '-') w = 1;
c = getchar();
}
while (c >= '0' && c <= '9') {
x = (x << 3) + (x << 1) + (c ^ 48);
c = getchar();
}
return w ? -x : x;
}
#pragma endregion
#undef ls
#undef rs
#define ls(x) t[x].l
#define rs(x) t[x].r
int root[1000001], cnt, pos[1000001], tmpl[51], tmpr[51], cntl, cntr, n;
struct node {
int w, l, r;
}t[20000001];
inl void maintain(int x) {
t[x].w = t[ls(x)].w + t[rs(x)].w;
}
inl void change(int &k, int l, int r, int p, int w) {
if (!k)k = ++cnt;
if (l == r)return (void)(t[k].w += w);
re mid = l + r >> 1;
if (p <= mid)change(ls(k), l, mid, p, w);
else change(rs(k), mid + 1, r, p, w);
maintain(k);
}
inl int query(int l, int r, int x, bool op) {
cntl = cntr = 0;
for (re i = l - 1; i; i -= lowbit(i)) tmpl[++cntl] = root[i];
for (re i = r; i; i -= lowbit(i))tmpr[++cntr] = root[i];
l = 1, r = n;
re mid, ans = 0;
while (l != r) {
mid = l + r >> 1;
if (x <= mid) {
if (op) {
for (re i = 1; i <= cntl; i++)ans -= t[rs(tmpl[i])].w;
for (re i = 1; i <= cntr; i++)ans += t[rs(tmpr[i])].w;
}
for (re i = 1; i <= cntl; i++)tmpl[i] = ls(tmpl[i]);
for (re i = 1; i <= cntr; i++)tmpr[i] = ls(tmpr[i]);
r = mid;
}
else {
if (!op) {
for (re i = 1; i <= cntl; i++)ans -= t[ls(tmpl[i])].w;
for (re i = 1; i <= cntr; i++)ans += t[ls(tmpr[i])].w;
}
for (re i = 1; i <= cntl; i++)tmpl[i] = rs(tmpl[i]);
for (re i = 1; i <= cntr; i++)tmpr[i] = rs(tmpr[i]);
l = mid + 1;
}
}
return ans;
}
signed main() {
n = read<int>();
re m = read<int>(), x, y;
ll ans = 0;
for (re i = 1; i <= n; i++) {
pos[i] = i;
for (re j = i; j <= n; j += lowbit(j)) change(root[j], 1, n, i, 1);
}
while (m--) {
x = read<int>(), y = read<int>();
if (x == y) {
writeln(ans);
continue;
}
ans -= query(1, pos[x] - 1, x, 1) + query(pos[x] + 1, n, x, 0);
ans -= query(1, pos[y] - 1, y, 1) + query(pos[y] + 1, n, y, 0);
for (re i = pos[x]; i <= n; i += lowbit(i))change(root[i], 1, n, x, -1);
for (re i = pos[y]; i <= n; i += lowbit(i))change(root[i], 1, n, y, -1);
swap(pos[x], pos[y]);
for (re i = pos[x]; i <= n; i += lowbit(i))change(root[i], 1, n, x, 1);
for (re i = pos[y]; i <= n; i += lowbit(i))change(root[i], 1, n, y, 1);
ans += query(1, pos[x] - 1, x, 1) + query(pos[x] + 1, n, x, 0);
ans += query(1, pos[y] - 1, y, 1) + query(pos[y] + 1, n, y, 0);
ans -= (pos[x] > pos[y] && x < y) || (pos[x] < pos[y] && x > y);
ans += (pos[x] > pos[y] && x > y) || (pos[x] < pos[y] && x < y);
writeln(ans);
}
}
|