Write a program that reads a file and builds a key-sequenced general list. After

Question

Write a program that reads a file and builds a key-sequenced general list. After the list is built, display it on the monitor. You may use any appropriate data structure, but it must have a key field and data. Two possibilities are a list of your favorite CDs or your friends' telephone numbers.

Explanation / Answer

following code is long but fulfills your requirment. #include #include #include #define FLUSH while (getchar() != ' ') // Global Declarations typedef int KEY_TYPE; typedef struct { KEY_TYPE key; char modifier; char *name; float gpa; } DATA; typedef struct nodeTag { DATA data; struct nodeTag* link; } NODE; // Function Declarations NODE* insertNode (NODE* pList, NODE* pPre, DATA item); bool searchList (NODE* pList, NODE** pPre, NODE** pCur, DATA* item); void printList (NODE* pList); NODE* buildList (char* fileID); bool getData (FILE* fpData, DATA* pData); void printListByGpa (NODE* pList, float target); void saveHiGpa (NODE* pList); float HIGPA = 0.0; // Header file to include functions (Not in text) //#include "P15-LIST.H" int main (void) { // Local Declarations NODE* pList; NODE* pPre; NODE* pCur; DATA data; double avrg; char more; // Statements printf("Begin list test driver "); // Build List pList = buildList("gpaDS.txt"); if (!pList) { printf("Error building chron file "); exit (100); } printList (pList); saveHiGpa (pList); while(1) { printf(" Print by gpa tests. "); printf("Enter target score: "); while (scanf ("%f", &data.gpa) != 1) { FLUSH; printf("Invalid number, please re-enter: "); } if(data.gpa==-1){ printf("Exiting... "); break; } printListByGpa (pList, data.gpa); } printf(" Tests complete. "); return 0; } // main /* ==================== insertNode ==================== This function inserts a single node into a linear list. Pre pList is pointer to the list; may be null pPre points to new node.s predecessor item contains data to be inserted Post returns the head pointer */ NODE* insertNode (NODE* pList, NODE* pPre, DATA item) { // Local Declarations NODE* pNew; // Statements if (!(pNew = (NODE*)malloc(sizeof(NODE)))) printf("Memory overflow in insert "), exit (100); pNew->data = item; if (pPre == NULL) { // Inserting before first node or to empty list pNew->link = pList; pList = pNew; } // if pPre else { // Inserting in middle or at end pNew->link = pPre->link; pPre->link = pNew; } // else return pList; } // insertNode /* ==================== searchList ==================== Given key value, finds the location of a node Pre pList points to a head node pPre points to variable to receive pred pCur points to variable for current node target is a pointer to the data with key being sought Post pCur points to first node with >= key -or- null if target > key of last node pPre points to largest node (*pCur)->data.key ) { *pPre = *pCur; *pCur = (*pCur)->link; } // while while (*pCur != NULL && target->key == (*pCur)->data.key && target->modifier>(*pCur)->data.modifier) { *pPre = *pCur; *pCur = (*pCur)->link; } if (*pCur != NULL && target->key == (*pCur)->data.key && target->modifier==(*pCur)->data.modifier) found = true; return found; } // searchList /* Traverse and print a linear list. Pre pList is a valid linear list Post List has been printed */ void printList (NODE* pList) { // Local Declarations NODE* pWalker; // Statements pWalker = pList; printf("List contains: "); printf(" PIN Name GPA "); printf(" === ============ ======= "); while (pWalker) { printf("%3d%c %s %.1f ", pWalker->data.key,pWalker->data.modifier,pWalker->data.name,pWalker->data.gpa); pWalker = pWalker->link; } // while printf(" "); return; } // printList /* Traverse and print a linear list. Pre pList is a valid linear list Post List has been printed */ void saveHiGpa (NODE* pList) { // Local Declarations NODE* pWalker; char* best_students_file="best_students.txt"; FILE* foutData; // Statements pWalker = pList; foutData=fopen(best_students_file,"w"); if(!foutData){ printf("Error opening file %s ", best_students_file); exit (210); } while (pWalker) { if(pWalker->data.gpa==HIGPA){ fprintf(foutData,"%3d%c %s %.1f ", pWalker->data.key,pWalker->data.modifier,pWalker->data.name,pWalker->data.gpa); } pWalker = pWalker->link; } // while fclose(foutData); return; } // printList /* Traverse and print a linear list. Pre pList is a valid linear list Post List has been printed */ void printListByGpa (NODE* pList, float target) { // Local Declarations NODE* pWalker; // Statements pWalker = pList; printf("List contains: "); while (pWalker) { if(pWalker->data.gpa>=target){ printf("%3d%c %s %.1f ", pWalker->data.key,pWalker->data.modifier,pWalker->data.name,pWalker->data.gpa); } pWalker = pWalker->link; } // while printf(" "); return; } // printList /* ==================== buildList ==================== This program builds a key-sequenced linear list. Pre fileID is file that contains data for list Post list built returns pointer to head of list */ NODE* buildList (char* fileID) { // Local Declarations DATA data; NODE* pList; NODE* pPre; NODE* pCur; FILE* fpData; // Statements pList = NULL; fpData = fopen(fileID, "r"); if (!fpData) { printf("Error opening file %s ", fileID); exit (210); } // if open fail while (getData (fpData, &data)) { if(HIGPA==0.0){ HIGPA=data.gpa; } else { if(HIGPAname = (char*) malloc(100*sizeof(char)); // Statements ioResult = fgets(buffer, 100, fpData); if(ioResult){ sscanf(buffer, "%d%c %[^;]%*c %f", &(pData->key), &(pData->modifier), pData->name, &(pData->gpa)); } return ioResult; } // getData void destroyList(NODE* pList, DATA data) { free(pList); return; }

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