-
Notifications
You must be signed in to change notification settings - Fork 1
/
reach_origin2.c
79 lines (59 loc) · 1.75 KB
/
reach_origin2.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
/*
Path To Reach Origin Problem on GeeksForGeeks
Problem Link: https://practice.geeksforgeeks.org/problems/paths-to-reach-origin/0
Note: This solution is based on Dynamic Programming (Memoization)
Author: Shyam Kumar
*/
#include <stdio.h>
#include <stdlib.h>
// #include <time.h>
// clock_t start, end;
unsigned long int **arr;
unsigned long int reachOrigin( int n, int m ) {
if( arr[n][m] == -1 ) {
/* If n = 0 (1st row) or m = 0 (1st column) then return 1
becoz from any cell in 1st row or 1st column, there
will be only 1 path to origin */
if( n == 0 || m == 0 )
return 1;
arr[n][m] = reachOrigin( n, m-1 ) + reachOrigin( n-1, m );
}
/* Remember: This statement is outside IF and not enclosed
inside ELSE */
return arr[n][m];
}
int main(int argc, char const *argv[])
{
start = clock();
int n, m, k, i, j;
unsigned long int ans;
printf("Enter the number of Test Cases:");
scanf("%d",&t);
while(t--) {
printf("Enter the number of rows:");
scanf("%d",&n);
printf("\nEnter the number of columns:");
scanf("%d",&m);
/* The reason for incrementing n and m is that we have to
find the total number of paths from (n, m) to
(0, 0) and not (1, 1). Therefore, we have to
increase 1 row and 1 column */
n++;
m++;
/* Dynamic memory Allocation of 2D array*/
arr = (unsigned long int**)malloc( n * sizeof( unsigned long int *) );
for( k = 0; k < n; k++ )
arr[k] = (unsigned long int*)malloc( m * sizeof( unsigned long int ) );
/* Initializing the 2D array */
for( i = 0; i < n; i++ ) {
for( j = 0; j < m; j++ ) {
arr[i][j] = -1;
}
}
ans = reachOrigin( n-1, m-1 );
printf("\n\nAns = %lu",ans);
}
// end = clock();
// printf("\nTime = %f", ((double)end-start))/CLOCKS_PER_SEC;
return 0;
}