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// 3025. Find the Number of Ways to Place People I
#include "leetcode.h"
/*
* you are given a 2d array 'points' of size 'n x 2' representing integer
* coordinates of some points on a 2d plane, where 'points[i] = [x_i, y_i]'.
* count the number of pairs of points '(a, b)' where 'a' is on the upper left
* side of 'b' and there are no other points in the rectangle they make,
* including the border. return the count.
*/
struct pair {
int x;
int y;
};
int cmp(const void *a, const void *b) {
struct pair *aa = (struct pair *)a, *bb = (struct pair *)b;
return aa->x != bb->x ? aa->x - bb->x : bb->y - aa->y;
}
int numberOfPairs(int **points, int pointsSize, int *pointsColSize) {
int i, j, y, ans = 0;
struct pair *list = (struct pair *)malloc(pointsSize * sizeof(struct pair));
for (int i = 0; i < pointsSize; i++) {
list[i].x = points[i][0];
list[i].y = points[i][1];
}
qsort(list, pointsSize, sizeof(struct pair), cmp);
for (int i = 0; i < pointsSize; i++) {
int y = INT_MIN;
for (int j = i + 1; j < pointsSize; j++) {
if (list[i].y >= list[j].y && y < list[j].y) {
ans++;
y = list[j].y;
}
}
}
free(list);
return ans;
}
int main() {
int p1i[3][2] = {{1, 1}, {2, 2}, {3, 3}},
p2i[3][2] = {{6, 2}, {4, 4}, {2, 6}},
p3i[3][2] = {{3, 1}, {1, 3}, {1, 1}};
struct two_d_arr *p1 =
two_d_arr_init(ARRAY_SIZE(p1i), ARRAY_SIZE(p1i[0]), p1i);
struct two_d_arr *p2 =
two_d_arr_init(ARRAY_SIZE(p2i), ARRAY_SIZE(p2i[0]), p2i);
struct two_d_arr *p3 =
two_d_arr_init(ARRAY_SIZE(p3i), ARRAY_SIZE(p3i[0]), p3i);
printf("%d\n",
numberOfPairs(p1->arr, p1->row_size, p1->col_size)); // expect: 0
printf("%d\n",
numberOfPairs(p2->arr, p2->row_size, p2->col_size)); // expect: 2
printf("%d\n",
numberOfPairs(p3->arr, p3->row_size, p3->col_size)); // expect: 2
two_d_arr_free(p1);
two_d_arr_free(p2);
two_d_arr_free(p3);
}
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