advent-of-code/03/day3_2.c
2018-12-03 16:20:56 +01:00

70 lines
1.6 KiB
C

#include <stdio.h>
#define SIZE 1000
struct Claim {
int left;
int top;
int width;
int height;
int id;
};
struct Claim parseClaim(char line[25]) {
struct Claim claim;
sscanf(line, "#%d @ %d,%d: %dx%d", &claim.id, &claim.left, &claim.top, &claim.width, &claim.height);
return claim;
}
void resetFields(int fabric [SIZE][SIZE]) {
for (int i=0; i<SIZE; i++) {
for (int j=0; j<SIZE; j++) {
fabric[i][j] = 0;
}
}
}
void setFields(struct Claim claim, int fabric [SIZE][SIZE]) {
for (int i=claim.left; i<claim.left+claim.width; i++) {
for (int j=claim.top; j<claim.top+claim.height; j++) {
fabric[i][j] += 1;
}
}
}
int verifyClaim(struct Claim claim, int fabric [SIZE][SIZE]) {
for (int i=claim.left; i<claim.left+claim.width; i++) {
for (int j=claim.top; j<claim.top+claim.height; j++) {
if (fabric[i][j] != 1) {
return 0;
}
}
}
return 1;
}
int main() {
int fabric [SIZE][SIZE];
FILE* input = fopen("input", "r");
char line [25];
// Looks like int[][] isn’t initialized to 0
resetFields(fabric);
int i = 0;
while (fgets(line, sizeof(line), input)) {
struct Claim claim = parseClaim(line);
setFields(claim, fabric);
}
input = fopen("input", "r");
while (fgets(line, sizeof(line), input)) {
struct Claim claim = parseClaim(line);
if (verifyClaim(claim, fabric) == 1) {
printf("Valid claim: %d\n", claim.id);
return 0;
}
}
return 0;
}