diff --git a/jihwan/week2/KBasePrimeCount.cpp b/jihwan/week2/KBasePrimeCount.cpp
new file mode 100644
index 0000000..ce500d5
--- /dev/null
+++ b/jihwan/week2/KBasePrimeCount.cpp
@@ -0,0 +1,48 @@
+#include <string>
+#include <vector>
+#include <iostream>
+#include <unordered_map>
+#include <math.h>
+using namespace std;
+
+//소수판별 함수
+bool isPrime(long long n) {
+    if(n==1) return false;
+    for(int i=2; i <= sqrt(n); i++) {
+        if(n%i==0) return false;
+    }
+    return true;
+}
+
+int solution(int n, int k) {
+    int answer = 0;
+    
+    vector<int> nums;
+    vector<string> nums2;
+    
+    //k진수로 변환
+    while(n>0) {
+        nums.push_back(n%k);
+        n/=k;
+    }
+    
+    //위 결과에서 거꾸로 숫자 찾아서 nums2에 삽입
+    string tmpNum="";
+    for(int i=nums.size()-1; i>=0; i--) {
+        if(nums[i]==0) {
+            if(!tmpNum.empty()) nums2.push_back(tmpNum);
+            nums2.push_back("0");
+            tmpNum="";
+        }
+        else tmpNum += to_string(nums[i]); 
+    }
+    if(!tmpNum.empty()) nums2.push_back(tmpNum);
+    
+    //소수인지 판별
+    for(int i=0; i<nums2.size(); i++) {
+        if(nums2[i]!="0") {
+            if(isPrime(stol(nums2[i]))) answer++;
+        }
+    }
+    return answer;
+}
diff --git a/jihwan/week2/N2ArraySlice.cpp b/jihwan/week2/N2ArraySlice.cpp
new file mode 100644
index 0000000..e53914c
--- /dev/null
+++ b/jihwan/week2/N2ArraySlice.cpp
@@ -0,0 +1,16 @@
+#include <string>
+#include <vector>
+
+using namespace std;
+
+vector<int> solution(int n, long long left, long long right) {
+    vector<int> answer;
+    for(long long i=left; i<=right; i++) {
+        //left~right 까지 행, 열을 구하고, 더 큰값을 answer에 넣기
+        int r,c;
+        r = i/n+1;
+        c = i%n+1;
+        answer.push_back(max(r,c));
+    }
+    return answer;
+}