1077：统计满足条件的4位数-信息学奥赛一本通

#include<algorithm>

#include<cmath>

#include<cstdio>

#include<iostream>

using namespace std;

int main(){

int n,tot=0;

cin>>n;

for(int i=1;i<=n;i++){

string s;

cin>>s;

int thousand=s[0]-'0';

int hundred=s[1]-'0';

int ten=s[2]-'0';

int one=s[3]-'0';

if(one-thousand-hundred-ten>0){

tot++;

}

}

cout<<tot;

return 0;

}