Question

Im not understanding how to loop this.

1) /* fill arrTestSizes in fRT with the variable arrTestSizes (hint: use a loop) */

Struct given:

typedef struct functionRuntimes
{
    char *szName;             //name of the function being tested
    double **arrRuntimes;         //run times
    double *arrAvg;            //average runtime
    int iNumRepeats;       //number of times to repeat each test size
    int iNumTestCaseSizes;   //number of test case sizes
    int *arrTestSizes;     //array containing the test case sizes
} functionRuntimes;

Answer 1

int i;
for (i = 0; i < fRT.iNumTestCaseSizes; ++i) {
    fRT.arrTestSizes[i] = arrTestSizes; // assuming you have a variable arrTestSizes and fRT
}