Hey anyone can tell me what is difference between these two code 1st is giving AC and second one is WA but according to me both are same plz help.

AC one

//HEADERS
int Mat[1025][1025];
int dp[1025][1025];

int main()
{
	int T;
	scanf("%d", &T);
	int t = 1;
	while(T--) {
		int d;
		memset(Mat, 0, sizeof Mat);
		memset(dp, 0, sizeof dp);
		int N;
		scanf("%d", &d);
		scanf("%d", &N);

		int x[N + 2];
		int y[N + 2];

		for(int i = 0; i < N; ++i) {
			int p;
			scanf("%d%d%d", &x[i], &y[i], &p);
			Mat[x[i]][y[i]] += p;
			for(int j = max(x[i] - d, 0); j <= min(x[i] + d, 1024); ++j) {
				for(int k = max(y[i] - d, 0); k <= min(y[i] + d, 1024); ++k) {
					dp[j][k] += Mat[x[i]][y[i]];
				}
			}
		}

		int cnt = 0;
		int X = 0;
		int Y = 0;

		for(int i = 0; i <= 1024; ++i) {
			for(int j = 0; j <= 1024; ++j) {
				if(dp[i][j] > cnt) {
					cnt = dp[i][j];
					X = i;
					Y = j;
				}
			}
		}
	
		printf("%d %d %d\n", X, Y, cnt);
	}
    return 0;
}

WA

//Headers
int Mat[1025][1025];
int dp[1025][1025];

int main()
{
	int T;
	scanf("%d", &T);
	int t = 1;
	while(T--) {
		int d;
		memset(Mat, 0, sizeof Mat);
		memset(dp, 0, sizeof dp);
		int N;
		scanf("%d", &d);
		scanf("%d", &N);

		int x[N + 2];
		int y[N + 2];

		for(int i = 0; i < N; ++i) {
			int p;
			scanf("%d%d%d", &x[i], &y[i], &p);
			Mat[x[i]][y[i]] += p;
			
		}

		for(int i = 0; i < N; ++i) {
			for(int j = max(x[i] - d, 0); j <= min(x[i] + d, 1024); ++j) {
				for(int k = max(y[i] - d, 0); k <= min(y[i] + d, 1024); ++k) {
					dp[j][k] += Mat[x[i]][y[i]];
				}
			}
		}

		int cnt = 0;
		int X = 0;
		int Y = 0;

		for(int i = 0; i <= 1024; ++i) {
			for(int j = 0; j <= 1024; ++j) {
				if(dp[i][j] > cnt) {
					cnt = dp[i][j];
					X = i;
					Y = j;
				}
			}
		}
	
		printf("%d %d %d\n", X, Y, cnt);
	}
    return 0;
}

hey can anybody tell me good algorithm for finding longest list of words with matching start and end letters
example -> acrush humblefool lilo tourist then longest list will be acrush humblefool lilo