LCS, LIS in C

lcs.c

#include <stdio.h>
#include <string.h>

char a[100];
char b[100];

void trace(int n, char t[][n + 1], int i, int j) {
    if (t[i][j] == 'u') {
        trace(n, t, i - 1, j);
    } else if (t[i][j] == 'l') {
        trace(n, t, i, j - 1);
    } else if (t[i][j] == 'c') {
        trace(n, t, i - 1, j - 1);
        printf("%c", a[i - 1]);
    }
}

int main() {
	scanf("%s %s", &a, &b);
	
	int m = strlen(a), n = strlen(b);
	int c[m + 1][n + 1];
	char t[m + 1][n + 1];
	
	for (int i = 0; i <= m; i++) {
		for (int j = 0; j <= n; j++) {
			c[i][j] = 0;
			t[i][j] = '#';
		}
	}
	
	for (int i = 1; i <= m; i++) {
		for (int j = 1; j <= n; j++) {
			if (a[i - 1] == b[j - 1]) {
				c[i][j] = c[i-1][j-1] + 1;
				t[i][j] = 'c';
			}
			else if (c[i - 1][j] > c[i][j - 1]) {
				c[i][j] = c[i - 1][j];
				t[i][j] = 'u';
			}
			else {
				c[i][j] = c[i][j-1];
				t[i][j] = 'l';
			}
		}
	}
	
	trace(n, t, m, n);
	
	return 0;
}

lis.c

#include <stdio.h>
#include <limits.h>

void trace(int arr[], int prev[], int i) {
    if (prev[i] == -1) {
        printf("%d ", arr[i]);
        return;
    }
    
    trace(arr, prev, prev[i]);
    printf("%d ", arr[i]);
}

int main()
{
    int n; scanf("%d", &n);
    int arr[n];
    int l[n];
    int prev[n];
    
    for (int i = 0; i < n; i++) {
        scanf("%d", &arr[i]);
        l[i] = 1;
        prev[i] = -1;
    }
    
    int max = INT_MIN, max_index = -1;
    for (int i = 1; i < n; i++) {
        for (int j = 0; j < i; j++) {
            if (arr[i] > arr[j] && l[j] + 1 > l[i]) {
                l[i] = l[j] + 1;
                prev[i] = j;
            }
            
            if (l[i] > max) {
                max = l[i];
                max_index = i;
            }
        }
    }
    
    trace(arr, prev, max_index);

    return 0;
}