suffix-array

Author: robot

src/codeTemplates/suffix_array.js

@@ -0,0 +1,119 @@
+export default {
+  title: "后缀树组",
+  logo: "",
+  list: [
+    {
+      text: "标准版",
+      problems: [],
+      codes: [
+        {
+          language: "cpp",
+          text: `
+          vector<int> sortCharacters(const string & text) {
+            int n = text.size();
+            vector<int> count(128), order(n);
+            for (auto c : text) {
+                count[c]++;
+            }    
+            for (int i = 1; i < 128; i++) {
+                count[i] += count[i - 1];
+            }
+            for (int i = n - 1; i >= 0; i--) {
+                count[text[i]]--;
+                order[count[text[i]]] = i;
+            }
+            return order;
+        }
+        
+        vector<int> computeCharClasses(const string & text, vector<int> & order) {
+            int n = text.size();
+            vector<int> res(n, 0);
+            res[order[0]] = 0;
+            for (int i = 1; i < n; i++) {
+                if (text[order[i]] != text[order[i - 1]]) {
+                    res[order[i]] = res[order[i - 1]] + 1;
+                } else {
+                    res[order[i]] = res[order[i - 1]];
+                }
+            }
+            return res;
+        }
+        
+        vector<int> sortDoubled(const string & text, int len, vector<int> & order, vector<int> & classfiy) {
+            int n = text.size();
+            vector<int> count(n), newOrder(n);
+            for (int i = 0; i < n; i++) {
+                count[classfiy[i]]++;
+            }
+            for (int i = 1; i < n; i++) {
+                count[i] += count[i - 1];
+            }
+            for (int i = n - 1; i >= 0; i--) {
+                int start = (order[i] - len + n) % n;
+                int cl = classfiy[start];
+                count[cl]--;
+                newOrder[count[cl]] = start;
+            }
+            return newOrder;
+        }
+        
+        vector<int> updateClasses(vector<int> & newOrder, vector<int> & classfiy, int len) {
+            int n = newOrder.size();
+            vector<int> newClassfiy(n, 0);
+            newClassfiy[newOrder[0]] = 0;
+            for (int i = 1; i < n; i++) {
+                int curr = newOrder[i];
+                int prev = newOrder[i - 1];
+                int mid = curr + len;
+                int midPrev = (prev + len) % n;
+                if (classfiy[curr] != classfiy[prev] || classfiy[mid] != classfiy[midPrev]) {
+                     newClassfiy[curr] = newClassfiy[prev] + 1;
+                } else {
+                     newClassfiy[curr] = newClassfiy[prev];
+                }
+            }
+            return newClassfiy;
+        }
+        
+        vector<int> buildSuffixArray(const string& text) {
+            vector<int> order = sortCharacters(text);
+            vector<int> classfiy = computeCharClasses(text, order);
+            int len = 1;
+            int n = text.size();
+            for (int i = 1; i < n; i <<= 1) {
+                order = sortDoubled(text, i, order, classfiy);
+                classfiy = updateClasses(order, classfiy, i);
+            }
+            return order;
+        }
+        
+        class Solution {
+        public:
+            string largestMerge(string word1, string word2) {
+                int m = word1.size(), n = word2.size();
+                string str = word1 + "@" + word2 + "*";
+                vector<int> suffixArray = buildSuffixArray(str); 
+                vector<int> rank(m + n + 2);
+                for (int i = 0; i < m + n + 2; i++) {
+                    rank[suffixArray[i]] = i;
+                }
+        
+                string merge;
+                int i = 0, j = 0;
+                while (i < m || j < n) {
+                    if (i < m && rank[i] > rank[m + 1 + j]) {
+                        merge.push_back(word1[i++]);
+                    } else {
+                        merge.push_back(word2[j++]);
+                    }
+                }
+                return merge;
+            }
+        };
+              `,
+        },
+      ],
+    },
+  ],
+  link: "",
+};