fix z_function

huggin · huggin · commit c4428ce44e18 · 2023-05-14T15:41:48.000-07:00
diff --git a/src/string/z-function.md b/src/string/z-function.md
@@ -33,7 +33,7 @@ vector<int> z_function_trivial(string s) {
 	int n = s.size();
 	vector<int> z(n);
 	for (int i = 1; i < n; i++) {
-		while (s[z[i]] == s[i + z[i]]) {
+		while (i + z[i] < n && s[z[i]] == s[i + z[i]]) {
 			z[i]++;
 		}
 	}
@@ -96,7 +96,7 @@ vector<int> z_function(string s) {
         if(i < r) {
             z[i] = min(r - i, z[i - l]);
         }
-        while(s[z[i]] == s[i + z[i]]) {
+        while(i + z[i] < n && s[z[i]] == s[i + z[i]]) {
             z[i]++;
         }
         if(i + z[i] > r) {

Original file line number	Diff line number	Diff line change
`@@ -33,7 +33,7 @@ vector<int> z_function_trivial(string s) {`
`33`	`33`	`int n = s.size();`
`34`	`34`	`vector<int> z(n);`
`35`	`35`	`for (int i = 1; i < n; i++) {`
`36`		`- while (s[z[i]] == s[i + z[i]]) {`
	`36`	`+ while (i + z[i] < n && s[z[i]] == s[i + z[i]]) {`
`37`	`37`	`z[i]++;`
`38`	`38`	`}`
`39`	`39`	`}`
`@@ -96,7 +96,7 @@ vector<int> z_function(string s) {`
`96`	`96`	`if(i < r) {`
`97`	`97`	`z[i] = min(r - i, z[i - l]);`
`98`	`98`	`}`
`99`		`- while(s[z[i]] == s[i + z[i]]) {`
	`99`	`+ while(i + z[i] < n && s[z[i]] == s[i + z[i]]) {`
`100`	`100`	`z[i]++;`
`101`	`101`	`}`
`102`	`102`	`if(i + z[i] > r) {`