#include <bits/stdc++.h>
#include <cstring>
using namespace std;
const int N=1e5+10;
const int INF=0x3f3f3f3f;
char a[255];
int main()
{
	cin >> a;
	int len=strlen(a),ans=0;
	for(int i=0;i<len;i++)
	{
		if(a[i]>='0' && a[i]<='9')
		{
			ans++;
		}
	}
	cout<<ans;
        return 0;
}
//ts2024stu008~~~~~~~~~~

有标志认证，属三无产品，请大家放心食用

#include <queue>
#include <math.h>
#include <stack>
#include <stdio.h>
#include <iostream>
#include <vector>
#include <iomanip>
#include <string.h>
#include <algorithm>
using namespace std;
#define int long long
#define float double
#define N 30000010
#define INF 0xc00000fd
#define scf scanf
#define ptf printf
#define gtc getchar
#define ptc putchar
#define psp ptc(' ')
#define pel ptc('\n')
#define pzr ptc('0')
#define fin for(int i = 1; i <= n; i++)
#define fim for(int i = 1; i <= m; i++)
#define fjn for(int j = 1; j <= n; j++)
#define fjm for(int j = 1; j <= m; j++)
#define rai fin	a[i] = read()
#define wct write(cnt)
#define pct print(cnt)
#define was write(ans)
#define pas print(ans)
queue<int> Q;
stack<int> S;
vector<int> V;
inline int wei(int n){
	int cnt = 0;
	while(n > 0){
		n /= 10;
		cnt++;
	}
	return cnt;
}
inline bool isPrime(int n){
	if(n < 2)
		return 0;
	for(int i = 2; i * i <= n; ++i)
		if(n % i == 0)
			return 0;
	return 1;
}
inline int read(string n){
	int x = 0, f = 1;
	ptf("%s", n.c_str());
	char c = gtc();
	while(c < '0'  ||  c > '9'){
		if(c == '-')
			f = -1;
		c = gtc();
	}
	while(c >= '0'  &&  c <= '9'){
		x = x * 10 + c - 48;
		c = gtc();
	}
	return x * f;
}
inline float input(string n){
	float x = 0, f = 1, x2 = 0, cnt = 0, i = 0;
	ptf("%s", n.c_str());
	char c = gtc();
	while(c < '0'  ||  c > '9'){
		if(c == '-')
			f = -1;
		c = gtc();
	}
	while(c >= '0'  &&  c <= '9'){
		x = x * 10 + c - 48;
		c = gtc();
	}
	c = gtc();
	while(c >= '0'  &&  c <= '9'){
		x2 = x2 * 10 + c - 48;
		cnt++;
		c = gtc();
	}
	for(; i < cnt; i++)
		x2 /= 10.0;
	return (x + x2) * f;
}
inline void write(int n) {
    if(n < 0){
        ptc('-');
        n = -n;
    }
    if(n > 9)
		write(n / 10);
    ptc(n % 10 + '0');
	return;
}
inline void print(float n){
	ptf("%lf\n", n);
	return;
}
#define input() input("")
#define read() read("")
int cnt;
char c[256]; 
inline void Main(){
	cin.getline(a, 255);
	for(int i = 0; i < strlen(a); i++)
		if(c <= '9' && c >= '0')
			cnt++;
	write(cnt);
	return;
}
signed main(signed argc, char **argv){
	Main();
	pel;
	return 0;
}

#include<iomanip>
#include<cmath>
#include<cstring>
using namespace std;
const int N=1e3+10;
const int INF=0x3f3f3f3f;
char a[N];
int ans;
int main()
{
	cin.getline(a,255);
	int lyn=strlen(a);
	for(int i=0;i<lyn;i++)
	{
		if(a[i]>=48&&a[i]<=57)
		{
			ans++;
		}
	}
	cout<<ans;
	return 0;
}
 

包没错！

#include<string.h>
#include<iostream>
using namespace std;
int main(){
	char a[10010];
	cin.getline(a,10000);
	int len=strlen(a);
	int sum=0;
	for(int i=0;i<len;i++){
		if(a[i]>='0' && a[i]<='9'){
			sum++;
		}
	}
	cout<<sum<<endl;
}

简单易懂👍 👍 👍

#include<bits/stdc++.h>
using namespace std;
int main(){
	string a;
	cin>>a;
	long long len=a.size(),sum=0;
	for(int i=0;i<=len-1;i++){
        if(a[i]>='0'&&a[i]<='9')
		sum++;
	
	}
    cout<<sum;	
}

#include<iostream> #include<cstring> using namespace std; const int N=255+10; const int INF=0x3f3f3f3f; char a[N]; int cnt; int main(){ cin.getline(a,255); int len=strlen(a); for(int i=0;i<len;i++) { if(a[i]>='0'&&a[i]<='9') { cnt++; } } cout<<cnt; }

#include<bits/stdc++.h>
#define LL long long
using namespace std;
const int INF=0x3f3f3f3f;
const int N=2e5+10;
string a;
int sum=0;
int main(){
	getline(cin,a);
	int b=a.size();
	for(int i=0;i<b;i++){
		if(a[i]>='0'&&a[i]<='9'){
			sum++;
		}
	}
	cout<<sum;
	return 0;
}

gets不被需要了，所以我来拯救它

#include <bits/stdc++.h>
using namespace std;
const int N=1e7+10;
const int INF=0x3f3f3f3f;
char a[2005];
int main()
{
	gets(a);
	int len=strlen(a),ans=0;
	for(int i=0;i<len;i++)
	{
		if(a[i]>='0' && a[i]<='9')
		{
			ans++;
		}
	}
	cout<<ans;
}

#include<iostream> #include<string> #include<cstring> using namespace std; const int N=2e5+10; char a[N]; int ans; int main() { cin.getline(a,255); int len = strlen(a); for(int i = 0;i <= len - 1;i++) { if(a[i] >= 48 && a[i] <= 57) { ans++; } } cout<<ans;

return 0;

}

#include<iostream> 
#include<cmath>
#include<iomanip>
#include <cstring>
using namespace std;
int INF=0x3f3f3f3f;
const int N=255+10;
int ans;
char a[N];
int main()
{
	cin.getline(a,255);
	int len=strlen(a);
	for(int i=0;i<=len-1;i++)
	{
		if(a[i]>=48 && a[i]<=57)
		{
			ans++;
		}
	}
	cout<<ans;
	return 0;
}

#include<cstdio>
#include<string>
#include<bits/stdc++.h>
#define LL long long
using namespace std;
const int INF=0x3f3f3f3f;
const int N=2e5+10;
string a;
int sum=0;
int main(){
	getline(cin,a);
	int b=a.size();
	for(int i=0;i<b;i++){
		if(a[i]>='0'&&a[i]<='9'){
			sum++;
		}
	}
	cout<<sum;
}

#include<bits/stdc++.h>
using namespace std;
string str;
int ans;
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	getline(cin,str);
	for(auto&i:str)
	{
		if(i>='0'&&i<='9')ans++;
	}
	printf("%d",ans);
	return 0;
}

#include <iostream>
#include <stack>
#include <cmath>
#include <vector>
#include <string.h>
#include <queue>
#include <stdio.h>
#include <iomanip>
#include <cstdio>
#include <algorithm>
#define int long long
using namespace std;
const int N = 1e5 + 10;
const int INF = 0x3f3f3f3f;
signed main()
{
	char a;
	int cnt = 0;
	while(cin >> a)
	{
		if(a >= '0' && a <= '9')
		{
			cnt++;
		}
	}
	cout << cnt << endl;
	return 0;
}

#include <cstdio>
#include <string>
using namespace std;

int main()
{
    int cnt = 0;
    string s;
    getline(cin, s);
    for (int i = 0; i < s.length(); i++) cnt += isdigit(s[i]);
    cout << cnt << endl;
    return 0;
}```