參考資訊:
https://www.cnblogs.com/grandyang/p/17796915.html
題目:
解答:
int min(int a, int b) { return (a > b) ? b : a; } int numberOfSubstrings(char* s) { const int MAX_LEN = 3; int r = 0; int cc = 0; int cnt[3]; int len = strlen(s); for (cc = 0; cc < 3; cc++) { cnt[cc] = -1; } for (cc = 0; cc < len; cc++) { cnt[s[cc] - 'a'] = cc; r += 1 + min(min(cnt[0], cnt[1]), cnt[2]); } return r; }