hdu1950 Bridging signals 最长递增子序列
用一个数组记下递增子序列长度为i时最小的len[i],不断更新len数组,最大的i即为最长递增子序列的长度
1 #include<cstdio> 2 #include<algorithm> 3 #define MAX 40010 4 using namespace std; 5 int a, T, n, len[MAX]; 6 int* lower(int &val, int R) //二分找值，返回下标 7 { 8 int L = 0, mid; 9 while (L < R) 10 { 11 mid = R - (R - L + 1) / 2; //保证至少减少1 12 if (len[mid] < val) L = mid + 1;//至少增加1 13 else R = mid; 14 } 15 return &len[R]; 16 } 17 int main() 18 { 19 scanf("%d", &T); 20 while (T--) 21 { 22 scanf("%d", &n); 23 int i, l = 0; 24 scanf("%d", &a); 25 len[0] = a; 26 for (i = 1; i < n; i++) 27 { 28 scanf("%d", &a); 29 if (a>=len[l]) len[++l] = a; 30 else *lower(a, l) = a; 31 // else *upper_bound(len,len+l+1,a) = a; 32 } 33 printf("%d\n", l + 1); 34 } 35 return 0; 36 }
