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ref: f7479653be7649267fd9e2096adf47862cea1a95
dir: /src_SigProc_FLP/SKP_Silk_sort_FLP.c/

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/* Insertion sort (fast for already almost sorted arrays):  */
/* Best case:  O(n)   for an already sorted array           */
/* Worst case: O(n^2) for an inversely sorted array         */

#include "SKP_Silk_typedef.h"
#include "SKP_Silk_SigProc_FLP.h"

void SKP_Silk_insertion_sort_increasing_FLP(
    SKP_float            *a,          /* I/O:  Unsorted / Sorted vector                */
    SKP_int              *index,      /* O:    Index vector for the sorted elements    */
    const SKP_int        L,           /* I:    Vector length                           */
    const SKP_int        K            /* I:    Number of correctly sorted positions    */
)
{
    SKP_float value;
    SKP_int   i, j;

    /* Safety checks */
    SKP_assert( K >  0 );
    SKP_assert( L >  0 );
    SKP_assert( L >= K );

    /* Write start indices in index vector */
    for( i = 0; i < K; i++ ) {
        index[ i ] = i;
    }

    /* Sort vector elements by value, increasing order */
    for( i = 1; i < K; i++ ) {
        value = a[ i ];
        for( j = i - 1; ( j >= 0 ) && ( value < a[ j ] ); j-- ) {
            a[ j + 1 ]     = a[ j ];     /* Shift value */
            index[ j + 1 ] = index[ j ]; /* Shift index */
        }
        a[ j + 1 ]     = value; /* Write value */
        index[ j + 1 ] = i;     /* Write index */
    }

    /* If less than L values are asked check the remaining values,      */
    /* but only spend CPU to ensure that the K first values are correct */
    for( i = K; i < L; i++ ) {
        value = a[ i ];
        if( value < a[ K - 1 ] ) {
            for( j = K - 2; ( j >= 0 ) && ( value < a[ j ] ); j-- ) {
                a[ j + 1 ]     = a[ j ];     /* Shift value */
                index[ j + 1 ] = index[ j ]; /* Shift index */
            }
            a[ j + 1 ]     = value; /* Write value */
            index[ j + 1 ] = i;        /* Write index */
        }
    }
}

void SKP_Silk_insertion_sort_decreasing_FLP(
    SKP_float            *a,          /* I/O:  Unsorted / Sorted vector                */
    SKP_int              *index,      /* O:    Index vector for the sorted elements    */
    const SKP_int        L,           /* I:    Vector length                           */
    const SKP_int        K            /* I:    Number of correctly sorted positions    */
)
{
    SKP_float value;
    SKP_int   i, j;

    /* Safety checks */
    SKP_assert( K >  0 );
    SKP_assert( L >  0 );
    SKP_assert( L >= K );

    /* Write start indices in index vector */
    for( i = 0; i < K; i++ ) {
        index[ i ] = i;
    }

    /* Sort vector elements by value, decreasing order */
    for( i = 1; i < K; i++ ) {
        value = a[ i ];
        for( j = i - 1; ( j >= 0 ) && ( value > a[ j ] ); j-- ) {
            a[ j + 1 ]     = a[ j ];     /* Shift value */
            index[ j + 1 ] = index[ j ]; /* Shift index */
        }
        a[ j + 1 ]     = value; /* Write value */
        index[ j + 1 ] = i;     /* Write index */
    }

    /* If less than L values are asked check the remaining values,      */
    /* but only spend CPU to ensure that the K first values are correct */
    for( i = K; i < L; i++ ) {
        value = a[ i ];
        if( value > a[ K - 1 ] ) {
            for( j = K - 2; ( j >= 0 ) && ( value > a[ j ] ); j-- ) {
                a[ j + 1 ]     = a[ j ];     /* Shift value */
                index[ j + 1 ] = index[ j ]; /* Shift index */
            }
            a[ j + 1 ]     = value; /* Write value */
            index[ j + 1 ] = i;     /* Write index */
        }
    }
}

void SKP_Silk_insertion_sort_increasing_all_values_FLP(
    SKP_float            *a,          /* I/O:  Unsorted / Sorted vector                */
    const SKP_int        L            /* I:    Vector length                           */
)
{
    SKP_float value;
    SKP_int   i, j;

    /* Safety checks */
    SKP_assert( L >  0 );

    /* Sort vector elements by value, increasing order */
    for( i = 1; i < L; i++ ) {
        value = a[ i ];
        for( j = i - 1; ( j >= 0 ) && ( value < a[ j ] ); j-- ) {    
            a[ j + 1 ] = a[ j ]; /* Shift value */
        }
        a[ j + 1 ] = value; /* Write value */
    }
}