#include<string> 
using namespace std;
int main(){
	freopen("cnt.in", "r", stdin);
        freopen("cnt.out", "w", stdout);
	int a[26]={0};
	string n;
	cin>>n;
	for(int i=0;i<n.size();i++){
		a[n[i]-97]++;
	}
	for(int i=0;i<26;i++){
		cout<<a[i]<<" ";
	}
	return 0;
}****

用getchar()边读边算，节省内存。

#include <cstdio>
using namespace std;
int main() {
    freopen("cnt.in", "r", stdin);
    freopen("cnt.out", "w", stdout);

    int ch;
    int letter[27] = {0};
    while ((ch = getchar()) != EOF) {
        letter[ch - 96]++;
    }
    for (int i = 1; i < 27; i++) {
        printf("%d ",letter[i]);
    }
  return 0;
}

#include #include using namespace std;

int main(){ freopen("cnt.in", "r", stdin); freopen("cnt.out", "w", stdout); string specialChar="abcdefghijklmnopqrstuvwxyz"; int cnt[26]={0}; string S; getline(cin, S); size_t i; for(i=0;i<S.length();i++){ size_t pos=specialChar.find(S[i]); if(pos!=string::npos){ cnt[pos]++; } } for(int i=0;i<26;i++){ cout<<cnt[i]<<" "; } return 0; }