matlab sub2ind利用c语言重写

matlab sub2ind利用c语言重写

#include <stdio.h>
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

typedef struct _sub2ind_res {
	unsigned char val;
	int id;
	int rows;
	int cols;
}sub2ind_res;

int sub2ind_uint8(unsigned char* ptr, int rows, int cols, int* x_id, int* y_id, int nums, sub2ind_res* res) {
	assert(nums < cols && nums < rows);

	if (res == NULL) {
		res = (sub2ind_res*)malloc(nums*sizeof(sub2ind_res));
		memset(res, 0, nums*sizeof(sub2ind_res));
	}

	for (int i = 0; i < nums; i++) {
		int x = x_id[i];
		int y = y_id[i];
		int id = y * cols + x;
		res[i].val = ptr[id];
		res[i].id = id;
		res[i].rows = y;
		res[i].cols = x;
	}

	return nums;
}

int main(int argc, char** argv) {

	srand((unsigned)time(NULL));

	unsigned char randData[100] = { 0 };
	for (int i = 0; i < 100; i++)
	{
		randData[i] = rand() % 100 + 1;
	}

	int rows = 10;
	int cols = 10;
	int x_id[] = { 1, 3, 6 };
	int y_id[] = { 2, 5, 8 };

	sub2ind_res res[3];

	sub2ind_uint8(randData, rows, cols, x_id, y_id, 3, res);

	for (int i = 0; i < 3; i++) {
		printf("data(%d, %d) = %d, id = %d\n", res[i].cols, res[i].rows, res[i].val, res[i].id);
	}

	
	return 0;
}