Slide 1Multiple-Dimensional ArraysMultiple-Subscripted ArraysSlide 4Slide 5Slide 6Dale RobertsDepartment of Computer and Information Science,Department of Computer and Information Science,School of Science, IUPUISchool of Science, IUPUICSCI 230ArraysMultidimensional ArraysDale Roberts, LecturerDale Roberts, [email protected]@cs.iupui.eduDale RobertsMultiple-Dimensional ArraysMultiple-Dimensional ArraysMultiple subscripted arrays Multiple subscripted arrays Arrays require at least two subscripts to identify a Arrays require at least two subscripts to identify a particular elementparticular elementANSI C standard allows at least 12 array subscriptsANSI C standard allows at least 12 array subscripts2D Arrays2D ArraysTables with rows and columns (Tables with rows and columns (mm by by nn array) array)Like matrices: specify row, then column Like matrices: specify row, then column Row 0Row 1Row 2Column 0 Column 1 Column 2 Column 3a[ 0 ][ 0 ]a[ 1 ][ 0 ]a[ 2 ][ 0 ]a[ 0 ][ 1 ]a[ 1 ][ 1 ]a[ 2 ][ 1 ]a[ 0 ][ 2 ]a[ 1 ][ 2 ]a[ 2 ][ 2 ]a[ 0 ][ 3 ]a[ 1 ][ 3 ]a[ 2 ][ 3 ]Row subscriptArray nameColumn subscriptA: scalar A[0]: 1D array1-Dimensional vectorA[0][0]: (2 subscripts)2D array (matrix)2-dimensional vectorA common error is to use math matrix notation a(1,2)Dale RobertsMultiple-Subscripted ArraysMultiple-Subscripted ArraysInitializationInitializationint b[2][2]int b[2][2] == {{{{ 1,1, 22 },}, {{ 3,3, 44 }} };};int c[3][2] = {{int c[3][2] = {{ 1,1, 22 },}, {{ 3,3, 44 },}, {{ 5,5, 66 }};}}; Initializers grouped by row in braces Initializers grouped by row in braces If not enough, unspecified elements set to zeroIf not enough, unspecified elements set to zeroint b[int b[ 22 ][][ 22 ]] == {{ {{ 11 },}, {{ 3,3, 44 }} }; }; Referencing elementsReferencing elementsSpecify Specify rowrow, then , then columncolumnprintf(printf( "%d","%d", b[b[ 00 ][][ 11 ]] );); 1 23 41 03 41 23 45 61 2 3 4 5 6Actual storage in the memory - rows by rows -“row-major”Dale Roberts1 /* Fig. 6.22: fig06_22.c2 Double-subscripted array example */3 #include <stdio.h>4 #define STUDENTS 35 #define EXAMS 467 int minimum( const int [][ EXAMS ], int, int );8 int maximum( const int [][ EXAMS ], int, int );9 double average( const int [], int );10 void printArray( const int [][ EXAMS ], int, int );1112 int main()13 {14 int student;15 const int studentGrades[ STUDENTS ][ EXAMS ] = 16 { { 77, 68, 86, 73 },17 { 96, 87, 89, 78 },18 { 70, 90, 86, 81 } };1920 printf( "The array is:\n" );21 printArray( studentGrades, STUDENTS, EXAMS );22 printf( "\n\nLowest grade: %d\nHighest grade: %d\n",23 minimum( studentGrades, STUDENTS, EXAMS ),24 maximum( studentGrades, STUDENTS, EXAMS ) );2526 for ( student = 0; student <= STUDENTS - 1; student++ )27 printf( "The average grade for student %d is %.2f\n", 28 student, 29 average( studentGrades[ student ], EXAMS ) );3031 return 0;32 }Each row is a particular student, each column is the grades on the exam. Proper naming of the #defined constants is important to convey meaning.Initialize variablesDefine functions to take double scripted arraysInitialize studentgrades[][]Call functions minimum, maximum, and averageconst indicates that the function does not modify the array.Dale Roberts3334 /* Find the minimum grade */35 int minimum( const int grades[][ EXAMS ], 36 int pupils, int tests )37 {38 int i, j, lowGrade = 100;3940 for ( i = 0; i <= pupils - 1; i++ )41 for ( j = 0; j <= tests - 1; j++ )42 if ( grades[ i ][ j ] < lowGrade )43 lowGrade = grades[ i ][ j ];4445 return lowGrade;46 }4748 /* Find the maximum grade */49 int maximum( const int grades[][ EXAMS ], 50 int pupils, int tests )51 {52 int i, j, highGrade = 0;5354 for ( i = 0; i <= pupils - 1; i++ )55 for ( j = 0; j <= tests - 1; j++ )56 if ( grades[ i ][ j ] > highGrade )57 highGrade = grades[ i ][ j ];5859 return highGrade;60 }6162 /* Determine the average grade for a particular exam */63 double average( const int setOfGrades[], int tests )64 {Why is it important to initialize lowGrade to the highest possible grade, and highGrade to the lowest possible grade?Dale Roberts65 int i, total = 0;6667 for ( i = 0; i <= tests - 1; i++ )68 total += setOfGrades[ i ];6970 return ( double ) total / tests;71 }7273 /* Print the array */74 void printArray( const int grades[][ EXAMS ], 75 int pupils, int tests )76 {77 int i, j;7879 printf( " [0] [1] [2] [3]" );8081 for ( i = 0; i <= pupils - 1; i++ ) {82 printf( "\nstudentGrades[%d] ", i );8384 for ( j = 0; j <= tests - 1; j++ )85 printf( "%-5d", grades[ i ][ j ] );86 }87 }Define functionThe array is: [0] [1] [2] [3]studentGrades[0] 77 68 86 73 studentGrades[1] 96 87 89 78 studentGrades[2] 70 90 86 81 Lowest grade: 68Highest grade: 96The average grade for student 0 is 76.00The average grade for student 1 is 87.50The average grade for student 2 is 81.75Program