题目:一个序列有N个数:A[1],A[2],…,A[N],求出最长非降子序列的长度。(见动态规划---LIS)
1 /* 2 题目:一个序列有N个数:A[1],A[2],…,A[N],求出最长非降子序列的长度。 3 */ 4 #include <stdio.h> 5 6 unsigned max_len( int [] , size_t ); 7 size_t b_point( int [] , size_t ); 8 int max(size_t , size_t ); 9 10 int main( void ) 11 { 12 13 int arr[] = { 4 , 5 , 3 , 3 , 3 , 3 , 6 , 5 , 1 , 2 }; 14 15 printf("%u " , max_len( arr , sizeof arr / sizeof arr[0] ) ); 16 17 return 0; 18 } 19 20 unsigned max_len( int a[] , size_t n ) 21 { 22 if ( n <= 1u ) 23 return n ; 24 25 size_t m = b_point ( a , n ) ; 26 27 return max( m , max_len ( a + m , n - m ) ) ; 28 29 } 30 31 size_t b_point ( int a[] , size_t n ) 32 { 33 size_t i ; 34 35 for ( i = 1u ; i < n ; i++ ) 36 if ( a[i-1] > a[i]) 37 return i - 0u ; 38 39 return i - 0u ; 40 } 41 42 int max( size_t n1 , size_t n2 ) 43 { 44 if ( n1 > n2 ) 45 return n1; 46 47 return n2; 48 }
1 /* 2 题目:一个序列有N个数:A[1],A[2],…,A[N],求出最长非降子序列的长度。 3 */ 4 #include <stdio.h> 5 6 unsigned max_len( int [] , size_t ); 7 size_t b_point( int [] , size_t ); 8 9 int main( void ) 10 { 11 int arr[] = { 4 , 5 , 3 , 3 , 3 , 3 , 6 , 5 , 1 , 2 }; 12 13 printf("%u " , max_len( arr , sizeof arr / sizeof arr[0] ) ); 14 15 return 0; 16 } 17 18 unsigned max_len( int a[] , size_t n ) 19 { 20 size_t len = 0u ; 21 while ( n > 0u ) 22 { 23 size_t mid = b_point( a , n ); 24 25 if ( mid > len ) 26 len = mid ; 27 28 a += mid ; 29 n -= mid ; 30 } 31 return len ; 32 } 33 34 size_t b_point ( int a[] , size_t n ) 35 { 36 size_t i ; 37 38 for ( i = 1u ; i < n ; i++ ) 39 if ( a[i-1] > a[i]) 40 return i - 0u ; 41 42 return i - 0u ; 43 }