feat: 添加P4267.cpp空模板文件并更新README文档

refactor: 重命名变量以提高代码可读性
将max_len改为maxlen，predecessor_k改为pk，max_lcsis改为maxlen，end_j改为endj，result_stack改为res，curr_i改为curri，curr_j改为currj

chore: 移动sort-matrix-by-diagonals.cpp文件位置
从src/8/27/移动到src/8/28/并更新内容

README.md

@@ -4,7 +4,12 @@
 >如果是递减序列就手写二分
 
 ## 区间dp
+### 步骤
 1. 根据问题推出dp含义
 2. 根据规则写出dp的状态转移公式
 3. 处理边界问题
 > dp[i][j], dp[0][0], dp[i][0], dp[0][j], dp[i][i], dp[j][j]
+### 
+1. 编辑距离 i-1,j i,j-1
+2. 合并石子 1~k,k+1~i
+3. 网捉蛇 1~k用j-1, k+1~i用1

src/8/27/opj2000.cpp

@@ -26,9 +26,9 @@ int main() {
 
     for (int i = 1; i <= n; ++i) {
 
-        int max_len = 0;
+        int maxlen = 0;
 
-        int predecessor_k = 0;
+        int pk = 0;
 
         for (int j = 1; j <= m; ++j) {
 
@@ -36,60 +36,58 @@ int main() {
             path[i][j] = {i - 1, j};
 
             if (a[i] == b[j]) {
-                if (max_len + 1 > dp[i][j]) {
+                if (maxlen + 1 > dp[i][j]) {
-                    dp[i][j] = max_len + 1;
+                    dp[i][j] = maxlen + 1;
-                    path[i][j] = {i - 1, predecessor_k};
+                    path[i][j] = {i - 1, pk};
                 }
             }
 
             if (b[j] < a[i]) {
-                if (dp[i - 1][j] > max_len) {
+                if (dp[i - 1][j] > maxlen) {
-                    max_len = dp[i - 1][j];
+                    maxlen = dp[i - 1][j];
-                    predecessor_k = j;
+                    pk = j;
                 }
             }
         }
     }
 
-    int max_lcsis = 0;
+    int maxlen = 0;
-    int end_j = 0;
+    int endj = 0;
 
     for (int j = 1; j <= m; ++j) {
-        if (dp[n][j] > max_lcsis) {
+        if (dp[n][j] > maxlen) {
-            max_lcsis = dp[n][j];
+            maxlen = dp[n][j];
-            end_j = j;
+            endj = j;
         }
     }
 
-    std::cout << max_lcsis << "\n";
+    std::cout << maxlen << "\n";
 
-    if (max_lcsis > 0) {
+    if (maxlen > 0) {
-        std::stack<ll> result_stack;
+        std::stack<ll> res;
-        int curr_i = n;
+        int curri = n;
-        int curr_j = end_j;
+        int currj = endj;
 
-        while (curr_i > 0 && curr_j > 0) {
+        while (curri > 0 && currj > 0) {
-            pii prev = path[curr_i][curr_j];
+            pii prev = path[curri][currj];
 
-            if (dp[curr_i][curr_j] > dp[prev.first][prev.second] && prev.second != curr_j) {
+            if (dp[curri][currj] > dp[prev.first][prev.second] && prev.second != currj) {
-                result_stack.push(a[curr_i]);
+                res.push(a[curri]);
             }
 
-            curr_i = prev.first;
+            curri = prev.first;
-            curr_j = prev.second;
+            currj = prev.second;
         }
 
         bool first = true;
-        while (!result_stack.empty()) {
+        while (!res.empty()) {
             if (!first) {
                 std::cout << " ";
             }
-            std::cout << result_stack.top();
+            std::cout << res.top();
-            result_stack.pop();
+            res.pop();
             first = false;
         }
         std::cout << "\n";
     }
-
-    return 0;
 }

src/8/28/P4267.cpp

@@ -0,0 +1,3 @@
+int main(){
+    
+}