转化成 lis 后 n2 搞就行
——代码
1 #include <cstdio> 2 #include <iostream> 3 #include <algorithm> 4 5 int n, max, ans; 6 int f[10001]; 7 struct node 8 { 9 int a, b; 10 }q[10001]; 11 12 inline int read() 13 { 14 int x = 0, f = 1; 15 char ch = getchar(); 16 for(; !isdigit(ch); ch = getchar()) if(ch == '-') f = -1; 17 for(; isdigit(ch); ch = getchar()) x = (x << 1) + (x << 3) + ch - '0'; 18 return x * f; 19 } 20 21 inline int Max(int x, int y) 22 { 23 return x > y ? x : y; 24 } 25 26 inline bool cmp(node x, node y) 27 { 28 return x.a < y.a; 29 } 30 31 int main() 32 { 33 int i, j, x, y; 34 n = read(); 35 for(i = 1; i <= n; i++) 36 { 37 q[i].a = read(); 38 q[i].b = read(); 39 } 40 std::sort(q + 1, q + n + 1, cmp); 41 for(i = 1; i <= n; i++) 42 { 43 max = 0; 44 for(j = 1; j < i; j++) 45 if(q[j].b < q[i].b) 46 max = Max(max, f[j]); 47 f[i] = max + 1; 48 ans = Max(ans, f[i]); 49 } 50 printf("%d ", ans); 51 return 0; 52 }