diff --git a/src/8/24/P1020.cpp b/src/8/24/P1020.cpp
new file mode 100644
index 0000000..9afaab2
--- /dev/null
+++ b/src/8/24/P1020.cpp
@@ -0,0 +1,59 @@
+#include <algorithm>
+#include <cstdint>
+#include <iostream>
+#include <vector>
+using ll = int64_t;
+
+int main(){
+    std::ios::sync_with_stdio(false);
+    std::cin.tie(nullptr);
+    std::vector<ll> v;
+    v.reserve(100000);
+    ll tmp;
+    while (std::cin >> tmp) {
+        v.push_back(tmp);
+    }
+    if (v.empty()) {
+        std::cout << "0\n0\n";
+        return 0;
+    }
+
+    std::vector<ll> f(v.size() + 1, 0);
+    f[1] = v[0];
+    ll maxdp = 1;
+
+    for (ll i = 1; i < v.size(); i++) {
+        ll h = v[i];
+        ll l = 1, r = maxdp, ans = 0;
+        while (l <= r) {
+            ll mid = (l + r) >> 1;
+            if (f[mid] >= h) {
+                ans = mid;
+                l = mid + 1;
+            } else {
+                r = mid - 1;
+            }
+        }
+        if (ans == 0) {
+            f[1] = std::max(f[1], h);
+        } else {
+            ll nxt = ans + 1;
+            if (nxt > maxdp) {
+                maxdp = nxt;
+                f[nxt] = h;
+            } else {
+                f[nxt] = std::max(f[nxt], h);
+            }
+        }
+    }
+    std::cout << maxdp << '\n';
+    std::vector<ll> sys;
+    sys.reserve(v.size());
+    for (ll h : v) {
+        auto it = std::lower_bound(sys.begin(), sys.end(), h);
+        if (it == sys.end()) sys.push_back(h);
+        else *it = h;
+    }
+    std::cout << sys.size() << '\n';
+    return 0;
+}
diff --git a/src/test.cpp b/src/test.cpp
index e1ca8b6..d5ad936 100644
--- a/src/test.cpp
+++ b/src/test.cpp
@@ -1,40 +1,22 @@
+#include <iostream>
 #include <vector>
-using namespace std;
+#include <algorithm>
 
-class Solution {
-public:
-    vector<int> findDiagonalOrder(const vector<vector<int>>& m) {
-        int x=0,y=0;
-        bool isup=true;
-        vector<int> res;
-        res.reserve(m.size());
-        #define isout (x<0||x>m.size()||y<0||y>m[0].size())
-        do{
-            res.push_back(m[x][y]);
-            if(isup){
-                if(x==0){
-                    ++y;
-                    isup=false;
-                }else{
-                    --x;
-                    ++y;
-                }
-            }else{
-                if(y==0){
-                    ++x;
-                    isup=true;
-                }else{
-                    ++x;
-                    --y;
-                }
-            }
-        }while(!(x==m.size()&&y==m[0].size()));
-        return res;
+int main() {
+    // 降序序列
+    std::vector<int> nums = {9, 7, 5, 3, 1};
+    int x = 4;
+    
+    // 使用upper_bound查找第一个比x大的元素
+    // 第三个参数是目标值x
+    // 第四个参数是自定义比较函数，保持降序的比较逻辑
+    auto it = std::upper_bound(nums.begin(), nums.end(), x, std::greater<int>());
+    
+    if (it != nums.end()) {
+        std::cout << "第一个比" << x << "大的数是: " << *it << std::endl;
+    } else {
+        std::cout << "没有比" << x << "大的数" << std::endl;
     }
-};
-
-int main(){
-
-    Solution s;
-    s.findDiagonalOrder({{1,2,3},{4,5,6},{7,8,9}});
+    
+    return 0;
 }
\ No newline at end of file