func_code_string: #include <bits/stdc++.h>   #pragma GCC optimize(2)   const int inf = 0x3f3f3f3f, Inf = 0x7fffffff;   const long long INF = 0x7fffffffffffffff;   const double eps = 1e-8;   unsigned int seed = 19260817;   const unsigned int _RAND_MAX_ = 4294967295u;   __inline__ __attribute__((always_inline)) unsigned int Rand() {     return seed = seed * 998244353u + 1000000007u;   }   template <typename _Tp>   _Tp gcd(const _Tp &a, const _Tp &b) {     return (!b) ? a : gcd(b, a % b);   }   template <typename _Tp>   __inline__ __attribute__((always_inline)) _Tp abs(const _Tp &a) {     return a > 0 ? a : -a;   }   template <typename _Tp>   __inline__ __attribute__((always_inline)) _Tp max(const _Tp &a, const _Tp &b) {     return a < b ? b : a;   }   template <typename _Tp>   __inline__ __attribute__((always_inline)) _Tp min(const _Tp &a, const _Tp &b) {     return a < b ? a : b;   }   template <typename _Tp>   __inline__ __attribute__((always_inline)) void chmax(_Tp &a, const _Tp &b) {     (a < b) && (a = b);   }   template <typename _Tp>   __inline__ __attribute__((always_inline)) void chmin(_Tp &a, const _Tp &b) {     (a > b) && (a = b);   }   template <typename _Tp>   __inline__ __attribute__((always_inline)) bool _cmp(const _Tp &a,                                                       const _Tp &b) {     return abs(a - b) <= eps;   }   template <typename _Tp>   __inline__ __attribute__((always_inline)) void read(_Tp &x) {     register char ch(getchar());     bool f(false);     while (ch < 48 || ch > 57) f |= ch == 45, ch = getchar();     x = ch & 15, ch = getchar();     while (ch >= 48 && ch <= 57)       x = (((x << 2) + x) << 1) + (ch & 15), ch = getchar();     if (f) x = -x;   }   template <typename _Tp, typename... Args>   __inline__ __attribute__((always_inline)) void read(_Tp &t, Args &...args) {     read(t);     read(args...);   }   __inline__ __attribute__((always_inline)) int read_str(char *s) {     register char ch(getchar());     while (ch ==     || ch ==   r  || ch ==   n ) ch = getchar();     register char *tar = s;     *tar = ch, ch = getchar();     while (ch !=     && ch !=   r  && ch !=   n  && ch != EOF)       *(++tar) = ch, ch = getchar();     return tar - s + 1;   }   const int N = 1200005;   struct node {     bool l, r;     int ans;     __inline__ __attribute__((always_inline)) node operator+(         const node &o) const {       return (node){l, o.r, ans + o.ans - (r == o.l)};     }   };   int L[N], R[N];   int t[N];   int a[N];   struct seg_tr {     struct Node {       int ls, rs;       node val1, val2;       bool tag;     } f[N << 1];     int node_cnt;     __inline__ __attribute__((always_inline)) void PushUp(int x) {       f[x].val1 = f[f[x].ls].val1 + f[f[x].rs].val1;       f[x].val2 = f[f[x].ls].val2 + f[f[x].rs].val2;     }     int build(int l, int r) {       int cur = ++node_cnt;       f[cur].tag = 0;       if (l == r) {         f[cur].ls = f[cur].rs = 0;         f[cur].val1 = (node){a[l] == 0, a[l] == 0, 1};         f[cur].val2 = (node){a[l] == 1, a[l] == 1, 1};         return cur;       }       int mid = (l + r) >> 1;       f[cur].ls = build(l, mid);       f[cur].rs = build(mid + 1, r);       PushUp(cur);       return cur;     }     __inline__ __attribute__((always_inline)) void upd(int cur) {       f[cur].tag ^= 1;       std::swap(f[cur].val1, f[cur].val2);     }     __inline__ __attribute__((always_inline)) void PushDown(int cur) {       if (f[cur].tag) {         upd(f[cur].ls);         upd(f[cur].rs);         f[cur].tag = 0;       }     }     void Update(int L, int R, int l, int r, int cur) {       if (L <= l && r <= R) {         upd(cur);         return;       }       PushDown(cur);       int mid = (l + r) >> 1;       if (L <= mid) Update(L, R, l, mid, f[cur].ls);       if (R > mid) Update(L, R, mid + 1, r, f[cur].rs);       PushUp(cur);     }     __inline__ __attribute__((always_inline)) int Query() {       return f[1].val1.ans;     }   } tr;   void MAIN() {     tr.node_cnt = 0;     int n;     read(n);     int len = 0;     for (int i = 1; i <= n; ++i) {       read(L[i], R[i]);       t[++len] = L[i];       t[++len] = R[i];     }     std::sort(t + 1, t + len + 1);     len = std::unique(t + 1, t + len + 1) - t - 1;     memset(a, 0, 8 * (len + 2));     for (int i = 1; i <= n; ++i) {       L[i] = std::lower_bound(t + 1, t + len + 1, L[i]) - t;       R[i] = std::lower_bound(t + 1, t + len + 1, R[i]) - t;       L[i] <<= 1;       R[i] <<= 1;       ++a[L[i]];       --a[R[i] + 1];     }     len <<= 1;     for (int i = 1; i <= len; ++i) a[i] += a[i - 1];     int root = tr.build(1, len);     int ans = 0;     for (int i = 1; i <= n; ++i) {       tr.Update(L[i], R[i], 1, len, root);       chmax(ans, tr.Query() >> 1);       tr.Update(L[i], R[i], 1, len, root);     }     printf( %d n , ans);   }   int main() {     int _;     read(_);     while (_--) MAIN();     return 0;   }   