Qbasic高精度数值计算问题.doc

高精度计算 1、高精加法 Rem gjdjf.txt CLS INPUT input two integer:, a$, b$ la = LEN(a$) lb = LEN(b$) a1$ = a$ b1$ = b$ IF lb la THEN SWAP a$, b$: SWAP la, lb n = la + 1 DIM a(n), b(n) FOR i = 1 TO n a(i) = 0 b(i) = 0 NEXT i FOR i = 1 TO la x$ = MID$(a$, n - i, 1) IF x$ = 0 AND x$ = 9 THEN a(i) = VAL(x$) ELSE PRINT a$ error data!: END END IF NEXT i FOR i = 1 TO lb x$ = MID$(b$, lb + 1 - i, 1) IF x$ = 0 AND x$ = 9 THEN b(i) = VAL(x$) ELSE PRINT b$ error data!: END END IF NEXT i FOR i = 1 TO la s = a(i) + b(i) a(i + 1) = a(i + 1) + s \ 10 a(i) = s MOD 10 NEXT i IF a(n) = 0 THEN n = n - 1 PRINT a1$; +; b1$; =; FOR i = 1 TO n PRINT MID$(STR$(a(n + 1 - i)), 2, 1); NEXT i 练习: 2高精度减法 Rem gjdjianf.txt CLS INPUT input two integer:, a$, b$ la = LEN(a$) lb = LEN(b$) a1$ = a$ b1$ = b$ IF lb la OR lb = la AND b$ a$ THEN SWAP a$, b$: SWAP la, lb: c$ = - n = la + 1 DIM a(n), b(n) FOR i = 1 TO n a(i) = 0 b(i) = 0 NEXT i FOR i = 1 TO la x$ = MID$(a$, la + 1 - i, 1) IF x$ = 0 AND x$ = 9 THEN a(i) = VAL(x$) ELSE PRINT a$ error data!: END END IF NEXT i FOR i = 1 TO lb x$ = MID$(b$, lb + 1 - i, 1) IF x$ = 0 AND x$ = 9 THEN b(i) = VAL(x$) ELSE PRINT b$ error data!: END END IF NEXT i FOR i = 1 TO la a(i) = a(i) - b(i) a(i + 1) = a(i + 1) + (a(i) 0) a(i) = a(i) - (a(i) 0) * 10 NEXT i PRINT a1$; -; b1$; =; DO WHILE a(n) = 0 AND n 1 n = n - 1 LOOP IF c$ = - THEN PRINT -; FOR i = 1 TO n PRINT MID$(STR$(a(n + 1 - i)), 2, 1); NEXT i 练习题: 3高精度乘法 Rem gjdcf.txt CLS INPUT input two integer:, a$, b$ la = LEN(a$) lb = LEN(b$) lc = la + lb DIM a(la), b(lb), c(lc) FOR i = 1 TO la: a(i) = 0: NEXT i FOR i = 1 TO lb: b(i) = 0: NEXT i FOR i = 1 TO lc: c(i) = 0: NEXT i FOR i = 1 TO la x$ = MID$(a$, la + 1 - i, 1) IF x$ = 0 AND x$ = 9 THEN a(i) = VAL(x$) ELSE PRINT a$ error data!: END END IF NEXT i FOR i = 1 TO lb x$ = MID$(b$, lb + 1 - i, 1) IF x$ = 0 AND x$ = 9 THEN b(i) = VAL(x$)