#include void bigmul(int x, int y, int r[]) { int base = 10000; int x2 = x / base; int x1 = x % base; int y2 = y / base; int y1 = y % base; int n1 = x1 * y1; int n2 = x1 * y2; int n3 = x2 * y1; int n4 = x2 * y2; r[3] = n1 % base; r[2] = n1 / base + n2 % base + n3 % base; r[1] = n2 / base + n3 / base + n4 % base; // 填空 r[0] = n4 / base; r[1] += r[2] / base; // 填空 r[2] = r[2] % base; r[0] += r[1] / base; r[1] = r[1] % base; } int main(int argc, char *argv[]) { int x[] = {0, 0, 0, 0}; bigmul(87654321, 12345678, x); printf("%d%d%d%d\n", x[0], x[1], x[2], x[3]); return 0; }