diff --git a/src/apple.c b/src/apple.c
index 766d543..629e042 100644
--- a/src/apple.c
+++ b/src/apple.c
@@ -3,15 +3,57 @@
 int n;
 int k;
 int A[100000];
+int mid=0; //global変数
+int j=0;
+int bag_num=0;
 
+int bag_judge(int m){
+  for(j=0;j<n;j++)
+  {
+    scanf("%d", &A[j]);
+    bag_num += (A[j]+ m - 1) / m; //mがリンゴを何個入れるか
+    //printf("%d\n",A[j]);
+  }
+  if(bag_num <= k)
+  {
+      return  1;    
+  }
+  else
+  {
+      return  0; 
+  }
+}
 
-int main(){
-  int i, lb, ub;
+
+int main(void){
+  int i,max,ub,lb;  
   scanf("%d%d", &n, &k);
-  for(i = 0; i < n; i++){
+  
+  for(i = 0; i < n; i++)
+  {
     scanf("%d", &A[i]);
+    if(max < A[i])
+    {
+      max = A[i];
+      ub = A[i];
+    }
   }
-
-
+  
+  lb = 0; //maxは上で定義してある
+  
+  
+  while(ub - lb > 1)
+  {
+    mid = (ub + lb)/2;
+    if(bag_judge(mid) == 1)
+    {
+      ub = mid;
+    }
+    else if(bag_judge(mid) == 0) 
+    {
+      lb = mid;
+    }
+    
+  printf("%d\n",lb);
   return 0;
 }
diff --git a/src/array.c b/src/array.c
index 13ed925..22c4fc3 100644
--- a/src/array.c
+++ b/src/array.c
@@ -1,18 +1,40 @@
-#include <stdio.h>
+#include <stdio.h> //配列の二分探索
 
 int n;
 int k;
 int A[100000];
-
+int mid=0; //global変数
 
 int main(){
-  int i, lb, ub;
+  int i,ub, lb;  
   scanf("%d%d", &n, &k);
+  
   for(i = 0; i < n; i++){
     scanf("%d", &A[i]);
   }
+  
+  lb=0,ub=n;
+  
+  if(A[n-1]<k)
+  {
+    mid=n;    
+  }
 
-
-
+  while(ub - lb > 1)
+  {
+    mid = (ub + lb)/2;
+    if(A[mid]>k)
+    {
+      ub = mid;
+      //printf("%d\n",mid);
+    }
+    else 
+    {
+       lb = mid;
+    }
+    //printf("%d\n",mid);
+  }
+  printf("%d\n",ub);
+  //printf("%d,%d",lb,ub);
   return 0;
-}
+}
\ No newline at end of file
diff --git a/src/spear.c b/src/spear.c
index 766d543..f3ce97b 100644
--- a/src/spear.c
+++ b/src/spear.c
@@ -3,15 +3,71 @@
 int n;
 int k;
 int A[100000];
+int mid=0; //global変数
+int j=0;
+int tree_num = 0;
+int tmp=0;
 
+int tree_judge(int m){
+  for(j=0;j<n;j++)
+  {
+    if(A[j] >= m)
+    { 
+      tree_num += A[j] / m; //切り上げないように
+    }
+  }
+  tmp=tree_num;
+  tree_num=0;
+  
+  //printf("mid=%d,tmp=%d\n",m,tmp);
+  if(tmp < k)
+  {
+      return 1;
+  }
+  else
+  {
+      return 0;    
+  }
+  //printf("tree_num=%d\n",tree_num);
+}
 
-int main(){
-  int i, lb, ub;
+
+int main(void){
+  int i,max,ub,lb,sum_length = 0;  
   scanf("%d%d", &n, &k);
-  for(i = 0; i < n; i++){
+  
+  for(i = 0; i < n; i++)
+  {
     scanf("%d", &A[i]);
+    sum_length = sum_length + A[i];
+    //printf("%d\n",A[i]);
+    
   }
-
-
+  
+  ub = sum_length / k; 
+  lb = 0;
+  
+  
+  while(ub - lb > 1)
+  {
+    mid = (ub + lb) / 2;
+    //printf("mid=%d\n",mid);
+    if(tree_judge(mid) == 1)
+    {
+      ub = mid;
+      //printf("lb=%d,ub=%d\n",lb,ub);
+    }
+    if(tree_judge(mid) == 0) 
+    {
+      lb = mid;
+     // printf("lb=%d,ub=%d\n",lb,ub);
+    }
+    if(k==0)
+    {
+      lb = 0;
+    }
+  }
+  //printf("%d\n",lb);
+  printf("%d",lb);
   return 0;
 }