Ultraviolet A 11732-strcmp () Anyone? (Trie)

Ultraviolet A 11732-strcmp () Anyone? (Trie)
Ultraviolet A 11732-strcmp () Anyone?

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Meaning: given some strings, we need to compare them by two or two times. (Note: if a character is the same, it must be compared to '\ 0' for two times)

Idea: Create a Trie tree. In each build process, the successor node is the same node. We need to compare the ans + val * 2 twice. Otherwise, the ans + val nodes are different.

Code:

#include 
 
  #include 
  
   const int N = 1005;const int MAXN = 4000005;int n;char str[N];long long ans;struct Node {    char c;    int val;} node[MAXN];int first[MAXN], next[MAXN], sz;void init() {    ans = 0;    sz = 1;    first[0] = 0; next[0] = 0; node[0].val = 0;}void insert(char *str) {    int u = 0, len = strlen(str);    for (int i = 0; i <= len; i++) {bool flag = true;int v, tmp;for (v = first[u]; v; v = next[v]) {    if (node[v].c == str[i]) {tmp = v;flag = false;ans += node[v].val * 2;    }    else ans += node[v].val;}if (flag) {    v = sz++;    node[v].c = str[i];    node[v].val = 0;    first[v] = 0;    next[v] = first[u];    first[u] = v;}else v = tmp;u = v;node[u].val++;    }}int main() {    int cas = 0;    while (~scanf("%d", &n) && n) {init();while (n--) {    scanf("%s", str);    insert(str);}printf("Case %d: %lld\n", ++cas, ans);    }    return 0;}