diff --git a/TangDou/Topic/PrefixAndSuffix/P1115_DP.cpp b/TangDou/Topic/PrefixAndSuffix/P1115_DP.cpp
index 7c206f7..422c3e6 100644
--- a/TangDou/Topic/PrefixAndSuffix/P1115_DP.cpp
+++ b/TangDou/Topic/PrefixAndSuffix/P1115_DP.cpp
@@ -3,7 +3,7 @@ using namespace std;
 const int N = 200100;
 int ans = INT_MIN;
 int n;
-int a[N], dp[N];
+int a[N], dp[N]; // dp[i]定义：前i个范围内，区间和的最大值
 
 int main() {
     cin >> n;
diff --git a/TangDou/Topic/【前缀和与差分】题单.md b/TangDou/Topic/【前缀和与差分】题单.md
index 6e2d0df..2e0bcfd 100644
--- a/TangDou/Topic/【前缀和与差分】题单.md
+++ b/TangDou/Topic/【前缀和与差分】题单.md
@@ -53,7 +53,7 @@ using namespace std;
 const int N = 200100;
 int ans = INT_MIN;
 int n;
-int a[N], dp[N];
+int a[N], dp[N]; // dp[i]定义：前i个范围内，区间和的最大值
 
 int main() {
     cin >> n;