关于C语言习题二

1、5*5数组中找出一行中最大的数，同时也是一列中最大的数。

#include<stdio.h>
#include<stdlib.h>
#include<time.h>
#define N 5
int main(){
    srand((unsigned)time(NULL));
    int i,j;
    int a[5][5];
    int row;
    int col;
    int max;
    int found=0;
do{
    for(i=0;i<N;i++){
        for(j=0;j<N;j++){
            a[i][j]=rand()%100;
        }
    }
    for(i=0;i<N;i++){
        for(j=0;j<N;j++){
            printf("%4d",a[i][j]);
        }
        printf("\n");
    }
    for(i=0;i<N;i++){
        max=a[i][0];
        row = i;
        col = 0;
        for(j = 0;j < N;j++){
            if(max<a[i][j]){
                max = a[i][j];
                col = j;
            }
        }
        for(j=0;j<N;j++){
            if(max>a[j][col]){
                break;
            }
        }
        if(j == N){
            found = 1;
            printf("num is %d, row = %d,col = %d\n",max,row,col);
        }
    }
}while(found == 0);//一直循环到找到saddle为止
    if(found==0){
        printf("not found saddle\n");
    }
    return 0;
}

 2、字符串逆序

#include<stdio.h>
int main(){
    void verse(char *a);
    char a[20];
    scanf("%[^\n]",a);
    verse(a);
    printf("%s\n",a);
    return 0;
}
void verse(char *a){
    int i = 0;
    int j = 0;
    int t;
    while(a[i]!='\0'){
        i++;
    }
    i--;
    while(j<i){
        t = a[j];
        a[j] = a[i];
        a[i] = t;
        j++;
        i--;
    }
    
}

3、整数转为任意进制的字符串输出。

#include<stdio.h>
int main(){
    void verse(char *a);
    char two(int n,char *a);
    char eight(int n,char *a);
    char ten(int n,char *a);
    char sixteen(int n,char *a);
    int n;
    char a[10];
    char b[10];
    char c[10];
    char d[10];    
    printf("please input a number:");
    scanf("%d",&n);
    two(n,a);
    eight(n,b);
    ten(n,c);
    sixteen(n,d);
    printf("%s\n",a);
    printf("%s\n",b);
    printf("%s\n",c);
    printf("%s\n",d);
    return 0;
}
void verse(char *a){
    int i = 0;
    int j = 0;
    int t;
    while(a[i]!='\0'){
        i++;
    }
    i--;
    while(j<i){
        t = a[j];
        a[j] = a[i];
        a[i] = t;
        j++;
        i--;
    }
    
}
char two(int n,char *a){
    int i = 0;
    while(n!=0){
        a[i] = (n % 2) + '0';
        i++;
        n = n / 2;
    }
    verse(a);
}
char eight(int n,char *a){
    int i = 0;
    while(n != 0){
         a[i] = (n % 8) + '0';
         i++;
         n = n / 8;
    }
    verse(a);
}
char ten(int n,char *a){
    int i = 0;
    while(n != 0){
         a[i] = (n % 10) + '0';
         i++;
         n = n / 10;
    }
    verse(a);  
}
char sixteen(int n,char *a){
    int i = 0;
    while(n != 0){
        switch(n%16){
            case 0: a[i] = 0+'0';break;
            case 1: a[i] = 1+'0';break;
            case 2: a[i] = 2+'0';break;
            case 3: a[i] = 3+'0';break;
            case 4: a[i] = 4+'0';break;
            case 5: a[i] = 5+'0';break;
            case 6: a[i] = 6+'0';break;
            case 7: a[i] = 7+'0';break;
            case 8: a[i] = 8+'0';break;
            case 9: a[i] = 9+'0';break;
            case 10: a[i] = 'A';break;
            case 11: a[i] = 'B';break;
            case 12: a[i] = 'C';break;
            case 13: a[i] = 'D';break;
            case 14: a[i] = 'E';break;
            case 15: a[i] = 'F';break;
        }
        i++;
        n = n / 16;
    }
    verse(a);
}

4、