Matrix Problem: For this problem, you are going to implement three functions called isDiagonal, isUpperTriangular and isLowerTriangular which determine whether the matrix (passed to the function as a parameter) is diagonal, upper- triangular and/or lower-triangular. The matrix is diagonal, if all the cells other than [i][i] are zero (in other words cell[i][j] = 0 if i != j). The matrix is upper triangular if all the cells [i][j] is 0, if i > j. The matrix is lower triangular, if all the cells [i][j] is 0 if i

? Function headers must be: o isUpperTriangular(intmatrix[][MAX_SIZE],intsize);

o isLowerTriangular(intmatrix[][MAX_SIZE],intsize);

o isDiagonal(intmatrix[][MAX_SIZE],intsize);

? [Assumption] The matrix passed to these function are square matrix (i.e., number of rows of the matrix = number of columns of the matrix). ? [Assumption] The maximum size of the matrices is 20 by 20 (as MAX_SIZE is defined 20 by 20 in the program).

? The main program MUST be as follows (and MUST NOT be changed at all: