有几件事
1.可变长度数组在C中是controversial，所以不要使用它们，请使用像malloc();这样的动态内存分配
1.您试图从一个变量定义数组大小，该变量的值是在运行时获得的。这是一个逻辑错误。您必须在计算hitDiceResults，woundDiceResults，saveDiceResults的值后移动定义。
1.请查看我的代码更改，这些更改由//<- code changed here突出显示

#include <stdio.h>
 #include <time.h>
 #include <stdlib.h>

 int main()
 {
     int attackingUnitSize, skill, strength, armorPenetration, attacks, damage= 0;
     int defendingUnitSize, toughness, save, invulnerableSave = 0;
     int woundRoll, saveRoll, simulations = 0;
     int hitSimulations, woundSimulations, saveSimulations = 0;
     int dice, successfulHits, successfulWounds, successfulSaves = 0;

     int hitOnes, hitTwos, hitThrees, hitFours, hitFives, hitSixes = 0;
     int woundOnes, woundTwos, woundThrees, woundFours, woundFives, woundSixes = 0;
     int saveOnes, saveTwos, saveThrees, saveFours, saveFives, saveSixes = 0;
     double avgHits, avgWounds, avgSaves = 0;

     int* hitDiceResults; //<- code changed here
     int* woundDiceResults; //<- code changed here
     int* saveDiceResults; //<- code changed here

     srand(time(0));

     printf("This program will ask for characteristics from warhammer 40k and ");
     printf("ask how many simulations you would like to run.\nIt will output the");
     printf(" average amount of successful hit rolls, wound rolls, damage and ");
     printf("save rolls made.\n");

     /*States that attacking units characteristics will be entered first*/
     printf("Enter the attacking units characteristics.\n");

     /*Gets unit size*/
     printf("Enter the units size: ");
     scanf("%d", &attackingUnitSize);

     /*Gets weapon/ballistic skill*/
     printf("Enter units weapon skill(WS) or ballistic skill(BS): ");
     scanf("%d", &skill);

     /*Gets units strength*/
     printf("Enter units strength(S): ");
     scanf("%d", &strength);

     /*Gets armor penetration*/
     printf("Enter units armor penetration(AP): ");
     scanf("%d", &armorPenetration);

     /*Gets number of attacks*/
     printf("Enter number of attacks: ");
     scanf("%d", &attacks);

     /*Gets damage*/
     printf("Enter the damage of the weapon: ");
     scanf("%d", &damage);

     /*States that defending units characteristics will be entered now*/
     printf("Enter the defending units characteristics.\n");

     /*Gets defending unit size*/
     printf("Enter units size: ");
     scanf("%d", &defendingUnitSize);

     /*Gets defending units toughness*/
     printf("Enter defending units toughness: ");
     scanf("%d", &toughness);

     /*Gets defending units save*/
     printf("Enter units Save: ");
     scanf("%d", &save);

     /*Gets defending units invulnerable save, if applicable*/
     printf("Enter defending units invulnerable save(if none, enter: 0): ");
     scanf("%d", &invulnerableSave);

     /*Gets number of simulations*/
     printf("How many simulations would you like to be done? ");
     scanf("%d", &simulations);

     /*Determines the lowest value for the wound roll*/
     if (strength >= (toughness * 2)){
         woundRoll = 2;
     }
     else if ((strength > toughness) && (strength < ((toughness * 2)))){
         woundRoll = 3;
     }
     else if (strength == toughness){
         woundRoll = 4;
     }
     else if ((strength < toughness) && ((strength * 2) > toughness)){
         woundRoll = 5;
     }
     else{
         woundRoll = 6;
     }

     /* Determines which save characterist to use */
     save += armorPenetration;
     if (invulnerableSave != 0){
         if (save < invulnerableSave){
             saveRoll = save;
         }
         else{
             saveRoll = invulnerableSave;
         }
     }
     else if(save > 6){
         saveRoll = 7;
     }
     else{
         saveRoll = save;
     }

     // Determines how many attacks are done and multiples that by simulations 
     attacks *= attackingUnitSize;
     hitSimulations = simulations * attacks;
     hitDiceResults = malloc(hitSimulations * sizeof(int)); //<- code changed here

     int i, j, k;
     for (i = 0; i < hitSimulations; i++){
         dice = rand() % 6 + 1;
         hitDiceResults[i] = dice;
       /*  printf("%d ", diceResults[i]); intended for debugging*/
     }

     //gets the number of hits for each dice face
     for (i = 0; i < hitSimulations; i++){
         if (hitDiceResults[i] == 1){
             hitOnes += 1;
         }
         else if (hitDiceResults[i] == 2){
             hitTwos += 1;
         }
         else if (hitDiceResults[i] == 3){
             hitThrees += 1;
         }
         else if (hitDiceResults[i] == 4){
             hitFours += 1;
         }
         else if (hitDiceResults[i] == 5){
             hitFives += 1;
         }
         else {
             hitSixes += 1;
         }
     }

     // Tallies up successful hits
     if (skill == 1){
         successfulHits = hitOnes + hitTwos + hitThrees + hitFours + hitFives + hitSixes;
         }
     else if (skill == 2){
         successfulHits = hitTwos + hitThrees + hitFours + hitFives + hitSixes;
         }
     else if (skill == 3){
         successfulHits = hitThrees + hitFours + hitFives + hitSixes;
         }
     else if (skill == 4){
         successfulHits = hitFours + hitFives + hitSixes;
         }
     else if (skill == 5){
         successfulHits = hitFives + hitSixes;
         }
     else {
         successfulHits = hitSixes;
         }

     woundDiceResults = malloc(successfulHits * sizeof(int));//<- code changed here
     //rolls dice for wounds after successful hits
     for(j = 0; j < successfulHits; j++){
         dice = rand() % 6 + 1;
         woundDiceResults[j] = dice;
     }

     //tallies up the wounds for each dice face
     for(j = 0; j < successfulHits; j++){
         if (woundDiceResults[j] == 1){
             woundOnes += 1;
         }
         else if (woundDiceResults[j] == 2){
             woundTwos += 1;
         }
         else if (woundDiceResults[j] == 3){
             woundThrees += 1;
         }
         else if (woundDiceResults[j] == 4){
             woundFours += 1;
         }
         else if (woundDiceResults[j] == 5){
             woundFives += 1;
         }
         else {
             woundSixes += 1;
         }
     }

         //tallies up the successful wound rolls
         if (woundRoll == 1){
             successfulWounds = woundOnes + woundTwos + woundThrees + woundFours + woundFives + woundSixes;
         }
         else if (woundRoll == 2){
             successfulWounds = woundTwos + woundThrees + woundFours + woundFives + woundSixes;
         }
         else if (woundRoll == 3){
             successfulWounds = woundThrees + woundFours + woundFives + woundSixes;
         }
         else if (woundRoll == 4){
             successfulWounds = woundFours + woundFives + woundSixes;
         }
         else if (woundRoll == 5){
             successfulWounds = woundFives + woundSixes;
         }
         else {
             successfulWounds = woundSixes;
         }

     saveDiceResults = malloc(successfulWounds * sizeof(int)); //<- code changed here
     //rolls dice equal to the number of successfulwounds    
     for (k = 0; k < successfulWounds; k++){
         dice = rand() % 6 + 1;
         saveDiceResults[k] = dice;
     }

     // tallies up the saves for each dice face rolled
     for(k = 0; k < successfulHits; k++){
         if (saveDiceResults[k] == 1){
             saveOnes += 1;
         }
         else if (saveDiceResults[k] == 2){
             saveTwos += 1;
         }
         else if (saveDiceResults[k] == 3){
             saveThrees += 1;
         }
         else if (saveDiceResults[k] == 4){
             saveFours += 1;
         }
         else if (saveDiceResults[k] == 5){
             saveFives += 1;
         }
         else {
             saveSixes += 1;
         }
     }

     if (saveRoll == 1){
         successfulSaves = saveOnes + saveTwos + saveThrees + saveFours + saveFives + saveSixes;
     }
     else if (saveRoll == 2){
         successfulSaves = saveTwos + saveThrees + saveFours + saveFives + saveSixes;
     }
     else if (saveRoll == 3){
         successfulSaves = saveThrees + saveFours + saveFives + saveSixes;
     }
     else if (saveRoll == 4){
         successfulSaves = saveFours + saveFives + saveSixes;
     }
     else if (saveRoll == 5){
         successfulSaves = saveFives + saveSixes;
     }
     else {
         successfulSaves = saveSixes;
     }

     /*Debugging
         printf("Hit rolls of 1 rolled: %d\n", hitOnes);
         printf("Hit rolls of 2 rolled: %d\n", hitTwos);
         printf("Hit rolls of 3 rolled: %d\n", hitThrees);
         printf("Hit rolls of 4 rolled: %d\n", hitFours);
         printf("Hit rolls of 5 rolled: %d\n", hitFives);
         printf("Hit rolls of 6 rolled: %d\n", hitSixes);
         */

     avgHits = successfulHits / simulations;
     printf("Average number of hits across %d simulations ", simulations);
     printf(" is: %f.\n", avgHits);

     free(hitDiceResults); //<- code changed here
     free(woundDiceResults); //<- code changed here
     free(saveDiceResults); //<- code changed here

     return 0;
 }