diff --git a/src/apple.c b/src/apple.c
index 766d543..bae178e 100644
--- a/src/apple.c
+++ b/src/apple.c
@@ -4,6 +4,14 @@ int n;
 int k;
 int A[100000];
 
+int p(int x){
+  int bag = 0;
+  for(int i = 0; i < n; i++){
+	bag += (A[i] + x -1)/x;
+  }
+  return (long long int) bag <= k;
+}
+  		
 
 int main(){
   int i, lb, ub;
@@ -11,7 +19,17 @@ int main(){
   for(i = 0; i < n; i++){
     scanf("%d", &A[i]);
   }
-
-
+  lb = 0;
+  ub = 100000 + 1;
+  while(ub - lb > 1){
+	int mid = (ub + lb) / 2;
+	if(p(mid)){
+		ub = mid;
+	}
+	else{
+		lb = mid;
+	};
+  }
+  printf("%d\n",ub);
   return 0;
 }
diff --git a/src/array.c b/src/array.c
index 13ed925..61bbb92 100644
--- a/src/array.c
+++ b/src/array.c
@@ -11,8 +11,13 @@ int main(){
   for(i = 0; i < n; i++){
     scanf("%d", &A[i]);
   }
-
-
-
+  lb = -1;
+  ub = n;
+  while(ub - lb > 1){
+	int mid = (ub + lb) / 2;
+	if(A[mid] >= k) ub = mid;
+	else lb = mid;
+  }
+  printf("%d\n",ub);
   return 0;
 }
diff --git a/src/spear.c b/src/spear.c
index 766d543..45eee36 100644
--- a/src/spear.c
+++ b/src/spear.c
@@ -4,6 +4,13 @@ int n;
 int k;
 int A[100000];
 
+int p(int x){
+  int spear = 0;
+  for(int i = 0; i < n; i++){
+	spear += A[i]/x;
+  }
+  return (long long int) spear >= k;
+}
 
 int main(){
   int i, lb, ub;
@@ -11,7 +18,17 @@ int main(){
   for(i = 0; i < n; i++){
     scanf("%d", &A[i]);
   }
-
-
+  lb = 0;
+  ub = 1000000000 + 1;
+  while(ub - lb > 1){
+	int mid = (ub + lb) / 2;
+	if(p(mid)){
+		lb = mid;
+	} /* lbはp(lb)が成り立つことがわかっている最大の数*/
+	else{
+		ub = mid;
+	};/* ubはp(ub)が成り立たないことがわかっている最小の数*/
+  }
+  printf("%d\n",lb);
   return 0;
 }
diff --git a/src/works.c b/src/works.c
index 766d543..64999a3 100644
--- a/src/works.c
+++ b/src/works.c
@@ -4,7 +4,7 @@ int n;
 int k;
 int A[100000];
 
-
+/*わかりませんでした。*/
 int main(){
   int i, lb, ub;
   scanf("%d%d", &n, &k);