configured gitignore, optimized matmult, fixed implicit conversion issue

.gitignore

@@ -0,0 +1,2 @@
+a.out
+.DS_Store

MLPP/KMeans/KMeans.cpp

@@ -171,14 +171,14 @@ namespace MLPP{
                 num[i] = 0;
             }
             
-            int den = 0;
+            double den = 0;
             for(int j = 0; j < r.size(); j++){
                 num = alg.addition(num, alg.scalarMultiply(r[j][i], inputSet[j]));
             }
             for(int j = 0; j < r.size(); j++){
                 den += r[j][i];
             }
-            mu[i] = alg.scalarMultiply(1/den, num);
+            mu[i] = alg.scalarMultiply(double(1)/double(den), num);
         }
         
     }

MLPP/LinAlg/LinAlg.cpp

@@ -78,8 +78,8 @@ namespace MLPP{
         }
         
     for(int i = 0; i < A.size(); i++){ 
-            for(int j = 0; j < B[0].size(); j++){
         for(int k = 0; k < B.size(); k++){ 
+            for(int j = 0; j < B[0].size(); j++){ 
                 C[i][j] += A[i][k] * B[k][j]; 
             } 
         }