我怎么都写不出啦！！我怎么都不对

有帮助望采纳
1.

#include<cstdio>
int main()
{
    int n;
    scanf("%d",&n);
    if(n%2!=0)
        printf("Odd");
    else
        printf("Even");
    return 0;
}

2.

#include<cstdio>
int main()
{
    int n;
    while(~scanf("%d",&n))
    {
        if(n>=90&&n<=100)
            printf("A\n");
        else if(n>=80&&n<90)
            printf("B\n");
        else if(n>=70&&n<80)
            printf("C\n");
        else if(n>=60&&n<70)
            printf("D\n");
        else if(n<60)
            printf("E\n");
        else
            printf("error!\n");
    }
    return 0;
}

第一题：

#include<cstdio>

int n;

int main()
{
    scanf("%d",&n);
    
    if(n % 2 == 0) printf("Even"); 
    
    else printf("Odd");
}

第二题：

#include<cstdio>

using namespace std;

int n; 

int main()
{
    while(scanf("%d",&n) != EOF)
        
        if(n > 100 or n < 0) 
        
            printf("error!\n");
             
        else if(90 <= n)
    
            printf("A\n");
    
        else if(89 >= n and n >= 80)
    
            printf("B\n");
    
        else if(79 >= n and n >= 70)
    
            printf("C\n"); 
    
        else if(n >= 69 and n >= 60)
    
            printf("D\n");
        
        else
        
            printf("E\n");
}

T1

#include <bits/stdc++.h>
using namespace std;
int m;
char a[100];
int main(){    
    scanf("%s", a);
    m = strlen(a);
    if (a[m - 1] % 2 == 0)
        printf("even");
    else printf("odd");
    return 0;
}

T2

#include <bits/stdc++.h>
using namespace std;
int point;
char ans='A';
int main(){    
    scanf("%d", &point);
    int x=point/10;
    if(x>=6) ans+=9-x;
    else ans='E';
    printf("%c",ans);
    return 0;
}