solution.cpp

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
static bool isInterleave(char *s1, char *s2, char *s3)
{
	int i, j;
	int len1 = strlen(s1);
	int len2 = strlen(s2);
	int len3 = strlen(s3);
	if (len1 + len2 != len3)
	{
		return false;
	}
	bool *table = malloc((len1 + 1) * (len2 + 1) * sizeof(bool));
	bool **dp = malloc((len1 + 1) * sizeof(bool *));
	for (i = 0; i < len1 + 1; i++)
	{
		dp[i] = &table[i * (len2 + 1)];
	}
	dp[0][0] = true;
	for (i = 1; i < len1 + 1; i++)
	{
		dp[i][0] = dp[i - 1][0] && s1[i - 1] == s3[i - 1];
	}
	for (i = 1; i < len2 + 1; i++)
	{
		dp[0][i] = dp[0][i - 1] && s2[i - 1] == s3[i - 1];
	}
	for (i = 1; i < len1 + 1; i++)
	{
		for (j = 1; j < len2 + 1; j++)
		{
			bool up = dp[i - 1][j] && s1[i - 1] == s3[i + j - 1];
			bool left = dp[i][j - 1] && s2[j - 1] == s3[i + j - 1];
			dp[i][j] = up || left;
		}
	}
	return dp[len1][len2];
}
int main(int argc, char **argv)
{
	if (argc != 4)
	{
		fprintf(stderr, "Usage: ./test s1 s2 s3\n");
		exit(-1);
	}
	printf("%s\n", isInterleave(argv[1], argv[2], argv[3]) ? "true" : "false");
	return 0;
}