C++ 解法, 执行用时: 29ms, 内存消耗: 408KB, 提交时间: 2020-10-29

#include<bits/stdc++.h>
using namespace std;
bool Is_magic(int num[],int digit,int target){
    for(int one=0;one<digit;one++){
        if(num[one]==target) return 1;
        for(int two=one+1;two<digit;two++){
            if(num[one]+num[two]==target) return 1;
            for(int three=two+1;three<digit;three++){
                if(num[one]+num[two]+num[three]==target) return 1;
                for(int four=three+1;four<digit;four++){
                    if(num[one]+num[two]+num[three]+num[four]==target) return 1;
                    for(int five=four+1;five<digit;five++){
                         if(num[one]+num[two]+num[three]+num[four]+num[five]==target) return 1;
                    }
                }
            }
        }
    }
    return false;
}
int main(){
    int l,r,ans=0;
    int num[11]={0};
    cin>>l>>r;
    for(int i=l;i<r+1;i++){
        int n = i;
        int digit = 0, suma = 0;
        while(n){
            int tmp = n%10;
            num[digit++] = tmp;
            suma += tmp;
            n /= 10;
        }
        if(suma&1) continue;
        if(Is_magic(num,digit,suma>>1)) ans++;
    }
    cout<<ans;
    return 0;
}

C++ 解法, 执行用时: 29ms, 内存消耗: 504KB, 提交时间: 2020-10-29

#include<bits/stdc++.h>
using namespace std;
bool Is_magic(int num[],int digit,int target){
    for(int one=0;one<digit;one++){
        if(num[one]==target) return 1;
        for(int two=one+1;two<digit;two++){
            if(num[one]+num[two]==target) return 1;
            for(int three=two+1;three<digit;three++){
                if(num[one]+num[two]+num[three]==target) return 1;
                for(int four=three+1;four<digit;four++){
                    if(num[one]+num[two]+num[three]+num[four]==target) return 1;
                    for(int five=four+1;five<digit;five++){
                         if(num[one]+num[two]+num[three]+num[four]+num[five]==target) return 1;
                    }
                }
            }
        }
    }
    return false;
}
int main(){
    int l,r,ans=0;
    int num[11]={0};
    cin>>l>>r;
    for(int i=l;i<r+1;i++){
        int n = i;
        int digit = 0, suma = 0;
        while(n){
            int tmp = n%10;
            num[digit++] = tmp;
            suma += tmp;
            n /= 10;
        }
        if(suma&1) continue;
        if(Is_magic(num,digit,suma>>1)) ans++;
    }
    cout<<ans;
    return 0;
}