Merge pull request #159 from SaiManasaPappu/master

* https://www.geeksforgeeks.org/maximum-sum-path-across-two-arrays/

* https://www.geeksforgeeks.org/coin-change-dp-7/ | https://www.geeksforgeeks.org/understanding-the-coin-change-problem-with-dynamic-programming/

* https://www.geeksforgeeks.org/minimum-positive-points-to-reach-destination/

dynamic_programming/C++/max_sum_path_in_two_arrays.cpp

@@ -0,0 +1,53 @@
+// For problem statement and I/O Format, visit: https://practice.geeksforgeeks.org/problems/maximum-sum-path-in-two-arrays/0
+
+#include<bits/stdc++.h>
+using namespace std;
+int main()
+ {
+     int test,m,n;
+     cin>>test;
+     while(test--){
+         cin>>n>>m;
+         int a1[n], a2[m];
+         for(int i=0;i<n;i++)
+         cin>>a1[i];
+         for(int i=0;i<m;i++)
+         cin>>a2[i];
+         int count=0,i=0,j=0,sum1=0,sum2=0;
+         while(i<n && j<m){
+             if(a1[i]==a2[j]){
+                 while (i < n &&  j < m && a1[i] == a2[j]){
+                     count = count + a1[i++];
+                     j++; 
+                 }
+                 count += max(sum1,sum2);
+                 sum1 = 0;
+                 sum2 = 0;
+             }
+             else if(a1[i]<a2[j]){
+                 sum1+=a1[i];
+                 i++;
+             }
+             else if(a1[i]>a2[j]){
+                 sum2+=a2[j];
+                 j++;
+             }
+         }
+         if(i<n || j<m){
+         if(i<n){
+             while(i<n){
+                 sum1+=a1[i++];
+             }
+         }
+         if(j<m){
+             while(j<m){
+                 sum2+=a2[j++];
+             }
+         }
+         count += max(sum1,sum2);
+         }
+         cout<<count<<endl;
+     }
+	//code
+	return 0;
+}

dynamic_programming/C++/min_coins_change.cpp

@@ -0,0 +1,50 @@
+#include<iostream>
+using namespace std;
+int main()
+ {
+	int test,n,amount;
+	cin>>test;
+	while(test--){
+	    cin>>amount>>n;
+	    int coin[n];
+	    for(int i=0;i<n;i++)
+	    cin>>coin[i];
+	    int am = amount+1;
+	    int a[n][am];
+
+	    for(int i=0;i<n;i++)
+	    a[i][0]=0;
+
+	    for(int i=1;i<am;i++)
+	    a[0][i] = (i%coin[0]==0 ? i/coin[0] : -1 );
+
+	    for(int i=1;i<n;i++){
+	        for(int j=1;j<am;j++){
+
+	            if(j<coin[i])
+	            a[i][j] = a[i-1][j] ;
+
+	            else if(j==coin[i])
+	            a[i][j]=1;
+
+	            else{
+
+	                if(a[i-1][j] == -1 && a[i][j-coin[i]] == -1)
+	                a[i][j] = -1;
+
+	                else if(a[i-1][j] == -1)
+	                a[i][j] = 1 + a[i][j-coin[i]] ;
+
+	                else if(a[i][j-coin[i]] == -1)
+	                a[i][j] = a[i-1][j];
+
+	                else
+	                a[i][j] = min(1 + a[i][j-coin[i]] , a[i-1][j]);
+
+	            }
+	        }
+	    }
+	    cout<<a[n-1][am-1]<<endl;
+	}
+	return 0;
+}

dynamic_programming/C++/minimum_pts_to_reach_destination.cpp

@@ -0,0 +1,46 @@
+// Problem statement, I/O formats clearly explained: https://practice.geeksforgeeks.org/problems/minimum-points-to-reach-destination/0
+
+#include <bits/stdc++.h>
+using namespace std;
+
+int mini=INT_MAX,**arr;
+
+//  arr is the main dp matrix
+
+void count(int r,int c,int cr,int cc,int csum,int locmin){
+
+    int newsum = csum+arr[cr][cc];
+    if(cr==r-1 && cc==c-1)
+    mini = min(mini,min(locmin,newsum)>0?1:(1-min(locmin,newsum)));
+
+    else if(cr<r-1 && cc<c-1){
+        count(r,c,cr+1,cc,csum+arr[cr][cc],min(locmin,csum+arr[cr][cc]));
+        count(r,c,cr,cc+1,csum+arr[cr][cc],min(locmin,csum+arr[cr][cc]));
+    }
+    else if(cr<r-1)
+    count(r,c,cr+1,cc,csum+arr[cr][cc],min(locmin,csum+arr[cr][cc]));
+
+    else if(cc<c-1)
+    count(r,c,cr,cc+1,csum+arr[cr][cc],min(locmin,csum+arr[cr][cc]));
+
+}
+int main()
+ {
+	int test,r,c;
+	cin>>test;
+	while(test--){
+	    mini=INT_MAX;
+	    cin>>r>>c;
+	    arr = (int **)malloc(r * sizeof(int *)); 
+         for (int i=0; i<r; i++) 
+         arr[i] = (int *)malloc(c * sizeof(int)); 
+	    for(int i=0;i<r;i++)
+	    for(int j=0;j<c;j++)
+	    cin>>arr[i][j];
+	    count(r,c,0,0,0,INT_MAX);
+	    cout<< mini << endl;
+
+	}
+	return 0;
+}
+