【C言語サンプル】
西暦から干支を求める

#include <stdio.h>
#include <time.h>
#include <string.h>
#include <assert.h>
static char *西暦干支変換strcpy版(int 西暦){
    static  char    output[1024];    
    switch ( 西暦%12 ) {
    case  0: strcpy(output,"申（さる）");   break;
    case  1: strcpy(output,"酉（とり）");   break;
    case  2: strcpy(output,"戌（いぬ）");   break;
    case  3: strcpy(output,"亥（い）");     break;
    case  4: strcpy(output,"子（ね）");     break;
    case  5: strcpy(output,"丑（うし）");   break;
    case  6: strcpy(output,"寅（とら）");   break;
    case  7: strcpy(output,"卯（う）");     break;
    case  8: strcpy(output,"辰（たつ）");   break;
    case  9: strcpy(output,"巳（み）");     break;
    case 10: strcpy(output,"午（うま）");   break;
    case 11: strcpy(output,"未（ひつじ）"); break;
    default:
        assert(0);
    }
    return  output;
}
static void 干支(int year){
    for(int i = 0;i < 12+1;i++){
        printf("%d+%2d年の干支は%s\n",
            year,
            i, 
            西暦干支変換strcpy版(year+i)
        );
    } 
}
int main(void){
	time_t t = time(NULL);
	struct tm *local = localtime(&t);
	printf("%04d/", 	local->tm_year + 1900);
	printf("%02d/", 	local->tm_mon + 1);
	printf("%02d\n", 	local->tm_mday);
	干支(local->tm_year + 1900);
}

#include <stdio.h>
#include <time.h>
#include <string.h>
#include <assert.h>
static char *西暦干支変換文字列版(int 西暦){
    switch ( 西暦%12 ) {
    case  0: return     "申（さる）";   
    case  1: return     "酉（とり）";   
    case  2: return     "戌（いぬ）";   
    case  3: return     "亥（い）"  ;    
    case  4: return     "子（ね）"  ;     
    case  5: return     "丑（うし）";   
    case  6: return     "寅（とら）";   
    case  7: return     "卯（う）"  ;     
    case  8: return     "辰（たつ）";   
    case  9: return     "巳（み）"  ;     
    case 10: return     "午（うま）";   
    case 11: return     "未（ひつじ）"; 
    default:
        assert(0);
    }
}
static void 干支(int year){
    for(int i = 0;i < 12+1;i++){
        printf("%d+%2d年の干支は%s\n",
            year,
            i, 
            西暦干支変換文字列版(year+i)
        );
    } 
}
int main(void){
	time_t t = time(NULL);
	struct tm *local = localtime(&t);
	printf("%04d/", 	local->tm_year + 1900);
	printf("%02d/", 	local->tm_mon + 1);
	printf("%02d\n", 	local->tm_mday);
	干支(local->tm_year + 1900);
}

#include <stdio.h>
#include <time.h>
#include <string.h>
#include <assert.h>
static const char *西暦干支変換配列版(int 西暦){
    static const char *干支[] ={
        [0]="申（さる）"    ,   
        [1]="酉（とり）"    ,   
        [2]="戌（いぬ）"    ,   
        [3]="亥（い）"      ,     
        [4]="子（ね）"      , 
        [5]="丑（うし）"    , 
        [6]="寅（とら）"    ,
        [7]="卯（う）"      ,         
        [8]="辰（たつ）"    , 
        [9]="巳（み）"      ,   
        [10]="午（うま）"   ,  
        [11]="未（ひつじ）" 
    };
    return      干支[西暦%12] ;
}
static void 干支(int year){
    for(int i = 0;i < 12+1;i++){
        printf("%d+%2d年の干支は%s\n",
            year,
            i, 
            西暦干支変換配列版(year+i)
        );
    } 
}
int main(void){
	time_t t = time(NULL);
	struct tm *local = localtime(&t);
	printf("%04d/", 	local->tm_year + 1900);
	printf("%02d/", 	local->tm_mon + 1);
	printf("%02d\n", 	local->tm_mday);
	干支(local->tm_year + 1900);
}