救命啊各位大佬！！！

int solve() {
int a,b,c;
FILE *fp = fopen("a.txt", "r");
if (fp != NULL) {
fscanf(fp, "%d %d %d", &a, &b, &c);
fclose(fp);
fp = NULL;
} else {
printf("a.txt not exits\n");
return -1;
}
fp = fopen("b.txt", "w");
if (fp != NULL) {
fprintf(fp, "%d %d %d", a,b,c);
fclose(fp);
fp = NULL;
}
}