some important printf syntax in C

#include<stdio.h>
//code by rajendra
main(){
    char str[30];
    int a=10,b=3;
float result;
result=((float)a)/b;
//result=(float)(a/b);
printf("%d\n",result);

    printf("jitendra"+2);//read after first two
    printf("\n%d %d");//garbage
    printf("\n%d\n",5,7);//output =5
    printf(3+"jitendra");//read after 3 char
    printf("\n");
    printf(3+"jitendra"+2);//read after first 2+3=5 character
    printf("\n");
    printf("%c\n","ABCDEF"[2]);//output C
    //scanf("%[^a]",str);//read the string till alphabate a
    //scanf("%[^\n]",str);//read till enter
    printf("%s",str);
   
    printf("percenatage symbol is %% char of the keyboard\n");//print % symbol
    printf("backslash is \\ character \n\n");
    printf("print double quota using \" and single is '\n\n");
}

C code of solving Quardratic equation

#include<stdio.h>
#include<math.h>
//code by rajendra
main(){
    int a,b,c,d;
    float root1,root2;
    printf("enter the coefficient of a,b,c \n");
    scanf("%d%d%d",&a,&b,&c);
    d=b*b-4*a*c;
    if(d>0){
        root1=(-b+sqrt(d))/(2*a);
        root2=(-b-sqrt(d))/(2*a);
        printf("first root is = %f and second root is = %f\n",root1,root2);
    }
    else
    printf("root are imaginory");
}

C header file 'stdlib' functions implementation

#include<stdio.h>
#include<stdlib.h>
//code by rajendra
main(){
    int ival,d_plc,sign;
    long lval;
    unsigned long ulval=362880L;
    float real1,real2=-57.12345;
    char str1[20]="-250",str2[20]="765.2345",str3[20],str4[33],*str5;
    ival=atoi(str1);
    lval=atol("12345678");
    real1=atof(str2);
    printf("%d %ld %.4f\n",ival,lval,real1);
    itoa(67,str3,8);
    ultoa(ulval,str4,2);
    printf("%s %s\n", str3,str4);
    str5=fcvt(real2,5,&d_plc,&sign);
    printf("%.5f conversion gives: String %s,Decimal is at place %d, Sign is %d",real2,str5,d_plc,sign);
  
}

C Code for easy matrix multiplication

#include<stdio.h>
//code by rajendra
    void readmat(int row,int col,int mat[][10]){
        int a,b;
        for(a=0;a<row;a++)
            for(b=0;b<col;b++)
                scanf("%d",&mat[a][b]);
       
    }
    void printmat(int row,int col,int mat[][10]){
        int a,b;
        for(a=0;a<row;a++)
            for(b=0;b<col;b++)
                scanf("%d",&mat[a][b]);
            printf("\n");
       
    }
    void multiply(int row1,int col1,int col2,int mat1[][10],int mat2[][10],int mat3[][10]){
        int a,b,c;
        for(a=0;a<row1;a++)
            for(b=0;b<col2;b++){
            int val=0;
                for(c=0;c<col1;c++)
                    val+=mat1[a][c]*mat2[c][b];
                    mat3[a][b]=val;
                   
           
        }
    }
main(){
    int r1,c1,r2,c2,m1[10][10],m2[10][10],m3[10][10];
    printf("Enter the order of first matrix");
    scanf("%d%d",&r1,&c1);
    printf("the first matrix\n");
    readmat(r1,c1,m1);
    printf("Enter the order of second matrix");
    scanf("%d%d",&r2,&c2);
    printf("the first matrix\n");
    readmat(r2,c2,m2);
   
    if(c1!=r2)
        printf("multiplicatio is not allowed\n");
    else
        {
            printf("multiplication of two matrix is= \n");
            multiply(r1,c1,c2,m1,m2,m3);
            printmat(r1,c2,m3);
        }
    }

C code for execution time calculation

#include<stdio.h>
#include<time.h>
//code by rajendra
main(){
    long int a;
    int b=10;
    clock_t start, end;
    start=clock();
    for(a=0;a<=10000000L;a++){
        switch(b)
        {
            case 1:break;
            case 2:break;
            case 3:break;
            case 4:break;
            case 5:break;
            case 6:break;
            case 7:break;
            case 8:break;
            case 9:break;
            case 10:break;
   
            end=clock();
            printf("Time taken by switch statement between the two execution : %f\n",(end-start)/CLK_TCK);
}
    }
}

C Code for decimal and Octal numbers

#include<stdio.h>
//code by rajendra lora
main(){
    int x=075,y=0117,z=0x60;
    printf("x=%x y=%X z=%o\n",x,y,z);
   
}