la/aoc2025
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

made 2-1 acceptably fast

Browse source
This commit is contained in:
laura 2025-12-08 22:26:56 +01:00
parent 0bc074c0b3
commit 61400d87e2
1 changed files with 70 additions and 13 deletions
Download patch file Download diff file Expand all files Collapse all files

83
2/main.c
View file

@ -18,6 +18,8 @@ char input[] =
int width = 0; int width = 0;
int height = 0; int height = 0;
uint64_t result = 0; uint64_t result = 0;
uint64_t result_2 = 0;
uint64_t parseNum(char* str, int* len){ uint64_t parseNum(char* str, int* len){
int i = 0; int i = 0;
@ -81,11 +83,60 @@ void sort_ranges(uint64_t* starts, uint64_t* ends, int len){
} }
} }
//splits ranges that go over a decimal overflow barrier into two (or if necessary more) ranges
void optimize_ranges(uint64_t* starts, uint64_t* ends, int* len){
for(int i = 0; i<(*len); i++){
if(numPlaces(starts[i])<numPlaces(ends[i])){
//printf("Range %lu - %lu crosses barrier\n", starts[i], ends[i]);
ends[*len] = ends[i];
ends[i] = power(10, numPlaces(starts[i]))-1;
starts[*len] = power(10, numPlaces(starts[i]));
(*len)++;
//printf("Split into %lu - %lu\n", starts[i], ends[i]);
//printf("and %lu - %lu\n\n", starts[*len], ends[*len]);
}
}
}
uint64_t sumup(uint64_t a, uint64_t b){
uint64_t res = 0;
for(uint64_t i = a; i<=b; i++){
res += i;
}
return res;
}
uint64_t sum_gauss(uint64_t a){
return (a*(a+1))/2;
}
uint64_t sumup_gauss(uint64_t a, uint64_t b){
return sum_gauss(b)-sum_gauss(a-1);
}
uint64_t check_range(uint64_t start, uint64_t end){
int num = numPlaces(start);
if(!(num%2)){
uint64_t div = 1+power(10, num/2);
uint64_t a = ((start+div-1)/div);
uint64_t b = (end)/div;
//uint64_t sum = sumup(a, b);
uint64_t sum = sumup_gauss(a, b);
//printf("Range %lu - %lu\nsumup: \t%lu\nsumup_gauss: \t%lu\n\n", start, end, sum, sum2);
return sum*div;
}
return 0;
}
int main(int argc, char *argv[]){ int main(int argc, char *argv[]){
clock_t start, end; clock_t start, end;
start = clock(); start = clock();
printf("INT_MAX: %d\n", INT_MAX); //printf("INT_MAX: %d\n", INT_MAX);
int i = 0; int i = 0;
int num_ranges = 1; int num_ranges = 1;
@ -96,8 +147,8 @@ int main(int argc, char *argv[]){
i++; i++;
} }
uint64_t starts[num_ranges]; uint64_t starts[num_ranges*2];
uint64_t ends[num_ranges]; uint64_t ends[num_ranges*2];
i = 0; i = 0;
int range_num = 0; int range_num = 0;
@ -112,18 +163,23 @@ int main(int argc, char *argv[]){
range_num++; range_num++;
} }
sort_ranges(starts, ends, num_ranges);
optimize_ranges(starts, ends, &num_ranges);
for(i = 0; i<num_ranges; i++){ for(i = 0; i<num_ranges; i++){
printf("checking range %lu-%lu\n\n", starts[i], ends[i]); //printf("checking range %lu-%lu\n", starts[i], ends[i]);
for(uint64_t o = starts[i]; o<=ends[i]; o++){ result_2 += check_range(starts[i], ends[i]);
//printf("checking %d for sillyness\n", o); //for(uint64_t o = starts[i]; o<=ends[i]; o++){
if(check_silly(o)){ // //printf("checking %d for sillyness\n", o);
result += o; // if(check_silly(o)){
printf("%lu is SILLY!\t\tcount is %lu\n", o, result); // result += o;
// //printf("%lu is SILLY!\t\tcount is %lu\n", o, result);
} //
} // }
//}
//printf("count: %lu\n", result);
//printf("count_2: %lu\n\n", result_2);
} }
//if(check_silly(1212)){ //if(check_silly(1212)){
@ -134,6 +190,7 @@ int main(int argc, char *argv[]){
end = clock(); end = clock();
printf("count: %lu\n", result); printf("count: %lu\n", result);
printf("count_2: %lu\n", result_2);
clock_t ticks_taken = end - start; clock_t ticks_taken = end - start;
double time_taken = ((double)ticks_taken)/CLOCKS_PER_SEC; double time_taken = ((double)ticks_taken)/CLOCKS_PER_SEC;
printf("time take: %f ticks\n", time_taken); printf("time take: %f ticks\n", time_taken);